RE: Off topic: English text explanation please

[Jack Aubert via sundial]

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I am a serious amateur musician, but unlike Peter, do not really enjoy anything 
earlier than late baroque.  I am also a word freak and this query sent me down 
some interesting linguistic and etymologic rabbit holes.  

 

It is only stating the obvious to observer that poetry is ipso facto ambiguous; 
a line or phrase can mean several things simultaneously or be incomprehensible 
to most (or all) people.  It is also obvious that the language has evolved so 
something that was idiomatic in the 17th century may not make sense now.  

 

The full original text in English is: 

 

Amyntas with his Phyllis fair,

In height of summer's sun,

Graz'd arm in arm their snowy flock;

And scorching heat to shun,

Under a spreading elm sat down,

Where Love's delightments done,

'Down, dillie down,' thus did they sing,

There is no life like ours,

No heav'n on earth to shepherd's cells,

No hell to princely bow'rs.

 

 

The first part is still relatively idiomatic in current English, although we 
can draw a discrete curtain over “love’s delightments” and wonder if there is 
some double entendre implied by “dillie dille down.”   But the last two lines 
make sense to us only if the “to” is replaced with “like”  as Peter suggested.  
The phrase “like to” is familiar to us from poetry but is no longer idiomatic.  
This is confirmed by the sense given to it by a German translation (thank you 
Google) 

 

Amyntas und seine schöne Phyllis hüteten,

als die Sommersonne am höchsten stand,

Arm in Arm ihre schneeweiße Herde,

und um der brütenden Hitze zu entfliehen,

ließen sie sich unter einer Schatten spendenden Ulme nieder.

Dort, nachdem sie die Freuden der Liebe genossen,

„Tra-la-la“, sangen sie:

„Kein Leben könnte schöner sein als das unsrige,

der Himmel auf Erden ist in der Hütte des Schafhirten,

die Hölle in königlichen Gemächern.

 

My German is weak but putting it back into contemporary English: 

 

There is no more beautiful life than ours

Heaven on earth is in a shepherd's hut.

Hell is in royal chambers.  

 

 

The word “bower” is interesting (thank you again Google) and comes from Old 
Norse like a lot of English does.  It originally meant a room or chamber.  It 
retained this sense in the 17th century when it more specifically meant a 
lady’s personal room or chamber in a hall or castle.  I speculate that this 
sense must have been influenced by French “boudoir” which means exactly that 
but comes from “bouder” meaning “to pout”: literally a boudoir is a pouting 
room.  By this time the Norman conquest had imprinted a heavy dose of French 
onto the Norse and Saxon middle English.   The modern meaning of bower is a 
pleasant shady place under trees or vines so Amyntas and Phyllis were enjoying 
their delightments under the elm tree which could be called a bower.   But the 
German translation, appropriately, kept the sense of “chambers.” 

 

So, to summarize: the original English does not quite make sense to a modern 
reader unless he just guesses that “to” means “like.”

 

Jack Aubert

 

 

From: sundial  On Behalf Of Peter Mayer
Sent: Friday, July 7, 2023 4:19 AM
To: sundial@uni-koeln.de; R. Hooijenga 
Subject: Re: Off topic: English text explanation please

 

Dear Rudolf,

I share your interest in 17th century madrigals.  (Although I'm a firm 
non-smoker, one of my favourites has the line "tobacco is like love..."). My 
interpretation is that this is a compressed form of poetical expression. 
Decompressed, I think, it would be: […] thus did they sing: ‘There is no life 
like ours, No heaven on earth [like] to shepherds' cells, no hell [like] to 
princely bowers’.

That is, there is an assumed parallelism with the first phrase.

best wishes,

Peter

On 7/07/2023 7:45:10, R. Hooijenga via sundial wrote:

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RE: Adjusting dial to new location

[Jack Aubert via sundial]

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I think I must be missing something here.  I cannot quite wrap my brain around 
what we would be trying to accomplish with a longitude adjustment.

 

A horizontal garden variety dial should tell apparent local solar time as long 
as it is correctly designed and the gnomon is pointing at the north celestial 
pole.  It can be moved to a new location and will continue to tell apparent 
local solar time as long as the whole thing is tilted so that it is at the 
latitude it was designed for and positioned so that the gnomon continues to 
point to the north celestial pole.  Now, If such a dial were to be tilted on 
its other axis so that it corresponds to the original longitude then I think it 
would tell local solar time at the original longitude.  This would appear to be 
wrong since it would not correspond to either local solar time or local civil 
time.   

 

AFAIK, the only way longitude comes into play in the design would be to make 
the dial conform more closely to civil time (leaving aside the equation of 
time) for example if the dial is located near the edge of the time zone.  AFAIK 
the only way to do this is to shift the dial plate around the vertical axis 
originating at the bottom end of the gnomon so that noon is no longer lined up 
with the gnomon and east west are no longer at right angles to the gnomon.  If 
such a dial were relocated then it would need some kind of longitude adjustment 
but would it not then tell something approximating civil time at its old 
location rather than the new one?

 

Is this wrong?  Is it possible to make a local longitude adjustment by tilting 
the whole thing on its polar axis?  

 

My spherical trig is almost nonexistent so I am trying to imagine all this 
visually and cannot quite see how it would work.  It seems to me that an 
east-west wedge would throw the gnomon off its polar axis.  

 

Jack Aubert  

 

 

From: sundial  On Behalf Of Steve Lelievre
Sent: Monday, April 3, 2023 7:47 PM
To: Rod Wall ; kool...@dickkoolish.com
Cc: 'Sundial sundiallist' 
Subject: Re: Adjusting dial to new location

 

Hi, Roderick,

My home internet connection is still non-functional so I can't fix it yet, but 
it does seem that I will have to add an extra test to handle southern 
hemisphere locations and reducing latitudes. Actually, I originally had a 
southern hemisphere check in there but took it out after convincing myself the 
same frame of reference (x axis east, y axis north, z up) applied to the 
spherical trigonometry irrespective of hemisphere. Ho hum.

Steve

 

On 2023-04-03 6:45 a.m., Rod Wall wrote:

Hi Steve,

For both examples below with all sundials at the same Longitude. The 
instructions indicate: 

Place the wedge-sundial assembly on a horizontal surface in a nice sunny 
location. Start with the higher end of the wedge to the north and the sides 
aligned on a north-south line and the sharp edge should be on an east-west line.

Example 1:



If you have a sundial that was designed for Latitude -20 deg. And relocate it 
at Latitude -50 deg.

Would you start with the higher end of the 30 deg wedge to the North. Or would 
it be to the South?



*

Example 2:



If you have a sundial that was designed for Latitude 50 deg. And relocate it at 
20 deg. 



Would you start with the higher end of the 30 deg wedge to the North. Or would 
it be to the South?

*



Please correct me if I am wrong. I think that both examples would be to the 
South.



Roderick.



 

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RE: Adjusting dial to new location

[Jack Aubert via sundial]

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I thought about this briefly.  I had always thought that the purpose of the 
shim or wedge adjustment was to tip the dial north or south so that dial is at 
the latitude it was originally designed for.  If the original dial has a 
built-in longitude correction, that could also be factored into a wedge which 
would have both a north-south and east-west axis.  But a wedge would not work 
if it moved the gnomon out of alignment with the with the rotation of the earth 
(or the celestial sphere).  I think a longitudinal adjustment would only work 
if he original dial had a time-zone offset included by rotating the hour lines 
with respect to the origin of the gnomon.  

 

Does this make sense?  It sounds like a good project for a 3-D printer.   

 

Jack

 

From: sundial  On Behalf Of Steve Lelievre
Sent: Sunday, April 2, 2023 5:16 PM
To: Michael Ossipoff 
Cc: Sundial List 
Subject: Re: Adjusting dial to new location

 

Michael,

Yes, I recognize that to get Mean Time involves Equation of Time adjustment and 
that Equation of Longitude can be handled there to give Standard Time (or DST).

But anyway, my inquiry was to seek an online wedge calculator. Nobody 
identified one and  a week seemed an adequate wait for responses, so I've just 
written one.  Anyone who's interested, please see

https://sundials.org/index.php/teachers-corner/sundial-construction/367-easy-dial-adjustment-for-your-latitude

Cheers,

Steve

 

On 2023-04-02 1:41 p.m., Michael Ossipoff wrote:

I just want to mention that the shim under the north or south edge of the dial 
is only for latitude. Longitude is corrected-for by changing the constant term 
of the Sundial-Time to Clock-Time conversion.

 

But usually Sundial-Time, Local True Solar Time, is what I’d want from a 
sundial.

 

On Sun, Mar 26, 2023 at 14:30 Steve Lelievre mailto:steve.lelievre.can...@gmail.com> > wrote:

Hi,

Can anyone point me to an existing online calculator for making a wedge 
to adjust a horizontal dial to a new latitude and longitude?

I am not asking for an explanation of how to do the calculation; I just 
want to be able to point people to a calculator that has already been 
proved on the internet. It should use the original location (latitude 
and longitude) and the new location to calculate the angle of slope of 
the wedge and the required rotation from the meridian.

Many thanks,

Steve


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Star Chasers of Senegal

[Jack Aubert via sundial]

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This video is only partly about sundials.  
https://schedule.wttw.com/series/54/NOVA/?tp=82542bbd-2867-4625-9c86-d4906d4da82b

 

It is about a Senegalese astronomer leading a team to set up a arrays of 
telescopes to measure a star’s occultation by an asteroid to determine its size 
and shape prior to a flyby by a NASA mission.  

But the video also digresses extensively into sundials, astrolabes and 
little-known Senegalese megaliths and some background material on Islamic 
astronomical research and takes a side trip to Istanbul.  

 

All these are of personal interest to me.  I lived in Senegal for three years 
and have spent time in Istanbul.  There are some beautiful videos of Dakar, 
Istanbul and several mosques.

 

Jack Aubert

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RE: Republican Calendar, Year 231

[Jack Aubert]

Michael,  

 

I don’t think anybody is seriously contemplating calendar reform.  I got a copy 
of the English version of the French Republican calendar from Frank King and  
It is hanging on a wall in my house.   I love it because it is historically 
interesting and, in retrospect, amusingly goofy.The names of the months 
were parodied by contemporaneous English writers as adjectives like “sneezy, 
chilly, and breezy.”  I would actually love to have a French version if anybody 
publishes one.  It would have to retain the juxtaposition of the normal 
calendar with the FRC calendar so you can tell what today’s day and month would 
have been called.  

 

I wonder if anybody can figure out a way to juxtapose a pre-Julian Roman 
calendar onto a modern calendar.  I think it would have to be arbitrarily reset 
somehow rather than fast forwarded.

 

Jack Aubert

 

From: sundial  On Behalf Of Michael Ossipoff
Sent: Saturday, September 17, 2022 9:02 PM
To: fabio.sav...@nonvedolora.it
Cc: Sundial sundiallist 
Subject: Re: Republican Calendar, Year 231

 

.

The first thing I want to emphasize is that calendar-reform is not going to 
happen. What to do? Just deal with the calendar that we have…the one that we’ve 
had for two millennia.(…but with its Gregorian-modernized leapyear-system). 
Don’t waste your time on calendar-reform, because, for one thing, it isn’t 
going to happen.

.

But suppose that there’s an alternative calendar that you like.  Calendar 
reform advocates are notoriously un-cooperative among eachother, & that further 
eliminates any chance of reform. But, even if the calendar were changed, then 
with the many different proposals around, what is the chance that the one that 
you’d like would be the one that somehow got adopted? Zilch. So that’s another 
reason to forget calendar-reform & just deal with the calendar that we have, 
the 2000-year-old Roman Calendar.

.

The OP was advocating for the French Republican Calendar, translated into your 
particular country’s language.

.

…but would its seasons be relevant to those who reside south of the equator, or 
in the tropical regions? No.

.

It would be a seasonal calendar based on the seasons of one particular 
lat-band. Hardly something that could be called internationally-fair or 
meaningful.

.

But let’s look at some other attributes of the French Republican Calendar (FRC):

.

It starts its year at the Autumnal Equinox, for those north of the equator.  (A 
more generally meaningful name for that equinox would be the Southward-Equinox.)

.

Why? Well, the French Republican government started around that time of the 
year.  That was a commendable government, & an improvement on what it replaced, 
but is its commemoration really what we need as the basis of our year-start 
choice?

.

There are good arguments for starting the year at the northern-hemisphere’s 
Vernal-Equinox, Winter-Solstice, or Summer-Solstice...or at the ancient Celts’ 
year-start at their Samhain holiday, which corresponds to our Holloween...or at 
the start of October, the Roman month that contains Samhain...or at the start 
of Scorpio the ecliptic-month that contains Samhain.

But I’ll spare you the year-start discussion, because, for one thing there 
isn’t going to be a new calendar. 

.

Resuming the attributes of the FRC:

.

The FRC is a year of 12 months of exactly 30 days each. Seems like a nice 
aesthetic simplification. But it leaves 5 or 6 days that aren’t any day of the 
week, & don’t belong to any month …not so neat after-all.  

.

Days that aren’t any day-of-the-week are called “blank-days”. They’re a mess, & 
that’s too obvious to need any explanation.

.

But, whatever reform-calendar you might like, its unlikely that it would be the 
one adopted, among the many proposals.   …as if there were even any chance of 
any new calendar being adopted anyway.

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RE: U.S. Senate approves bill to make daylight saving time permanent

[Jack Aubert]

Not exactly.  In Paris, lunch time is at 1:00.  That is very close to solar 
noon.  Paris is just a few degrees east of London.  

Maybe lunch time is at solar transit.  

 

From: sundial  On Behalf Of Kurt Niel
Sent: Wednesday, March 16, 2022 7:18 AM
To: Steve Lelievre 
Cc: Sundial List 
Subject: Re: U.S. Senate approves bill to make daylight saving time permanent

 

Noon is noon while the sun is up in the sky - over and out.

 

Kurt Niel mailto:kepler...@gmail.com> > schrieb am Mi., 
16. März 2022, 12:12:

It is still a shame, that DST is really that prominent. I stay in Europe and 
hope we can get rid of it - dammned DST.

 

I am still very emotional about it and see it as one of many homan made 
mistakes.

 

Kurt

 

Steve Lelievre mailto:steve.lelievre.can...@gmail.com> > schrieb am Di., 15. März 2022, 22:51:


It seems the USA may be getting ready to abolish seasonal clock 
changes.  The proposal has just passed in the Senate but still has to be 
accepted by the House of Representatives, so we can't celebrate yet. ( 
https://www.reuters.com/world/us/us-senate-approves-bill-that-would-make-daylight-savings-time-permanent-2023-2022-03-15/
 
)

If it happens, Canada would quickly follow. In fact, here in British 
Columbia it's already in law that we will switch to permanent DST once 
Washington (state), Oregon and California have switched. The EU is 
already on the same path but things have got bogged down with some 
member countries yet to decide which timezone to adopt. EU-wide 
preparations were further delayed due to the pandemic ( 
https://www.thelocal.it/20211029/clocks-to-go-back-in-italy-despite-eu-deal-on-scrapping-hour-change/
 
).

I would have preferred permanent Standard Time over permanent 
Daylight-saving Time but, even so, I hope the plans proceed. It will 
certainly simplify the my designs for Civil Time sundials and Equation 
Of Time signage.

Cheers, Steve

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RE: Telling time with a rope?

[Jack Aubert]

I tired searching for “pommeau de ciel” and “pommeau des cieux”, which not 
surprisingly I did not recognize in either English or French.  Pommel is 
Pommeau in French.  I mostly got hits for shower heads and gear shift knobs… 
but did find a reference to the original French on Google Books:

 

https://books.google.com/books?id=BVtcMAAJ 

 
&pg=PA108&lpg=PA108&dq=pommeau+de+ciel&source=bl&ots=4NKJk6haHD&sig=ACfU3U0xr9oORL7S6zs-nKRg-NnTizDKfQ&hl=en&sa=X&ved=2ahUKEwiD_trVyqr2AhVlkeAKHacJDbwQ6AF6BAghEAM#v=onepage&q=pommeau%20de%20ciel&f=false

 

But reading the text, it does appear that “pommel of the sky” could only refer 
to Polaris, as Steve surmises.  That being said, I have to suspect that Guy 
Marchant came up with this method, that would be beyond the interest the vast 
majority of shepherds, on his own.  A shepherd, who is probably illiterate, is 
supposed to identify a star and remember to adjust its time position throughout 
the year?  Also, why would he care what time it is at night?  Maybe they taught 
that in advanced shepherd class.  

 

Jack

 

 

 

From: sundial  On Behalf Of Steve Lelievre
Sent: Thursday, March 3, 2022 2:17 PM
To: sundial@uni-koeln.de
Subject: Re: Telling time with a rope?

 

Hi,

 

 I think the pommel of the sky refers to the celestial north pole, i.e. where 
we see the Pole Star or Polaris.

 

Then, on the summer solstice hold a plumb line in front of you such that it 
obscures the Pole Star, and find another circumpolar that is also hidden by the 
plumbline.  In the rest of the year, the angular displacement of this second 
star tells you how far from midnight you are, provided you make an adjustment 
of 1 hour per half month.

 

For the method to work, you need to have established midnight on the summer 
solstice. This is done by fixing two plumb lines one behind the other, so that 
they are aligned to the solstice's midday sun, i.e. they show you the meridian. 
I think the text is saying that on the day of the summer solstice, as the 
shepherd faces north looking through the plumb lines, if Cancer is seen 
slightly to the east and Capricorn slightly to the west, then it is midnight 
(presumably that's only in the British Isles).

 

I got this  from a rather quick scan of the text, so I may have missed 
something. There's also discussion of the learning the rising positions of the 
signs of the zodiac but I don't quite follow how it relates to the rest.

 

Steve

 

 

 

 

 

 

 

On 2022-03-03 10:11 a.m., Dan-George Uza wrote:

Hello,

 

In the "Kalendar and Compost of Shepherds" by Guy Marchant, an illustrated work 
translated from French into English in the early 1500s, there is a chapter with 
the following title: "Shepherds practise their quadrant at night as you see by 
the figure hereafter". Could someone more versed in old English please explain 
how this technique actually worked? I attach the relevant pages from the 1931 
edition. 

 

Thanks,

 

-- 

Dan-George Uza

 


 

 

Virus-free.  

 www.avast.com 





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RE: Is this an educational sundial, or a 'NON-dial'?

[Jack Aubert]

The author’s web site seems to be an attempt to monetize has plans for 
analemmatic dials claiming that the whole thing is educational.  There is even 
a link for franchised distributors!  I suppose it would be interesting to see 
what kind of information is contained in the book.  The drawing on the cover 
is, like a stopped watch, occasionally correct – but only once a day and only 
if you decide what part of the shadow to use.  It looks like a scam.

 

My personal view of analemmatic dials is that they can be decorative and even 
entertaining, but are not very educational at all.  It is hard enough for me 
visualize the projection of a conic section onto a horizontal plane and relate 
it to the sky and the sun let alone explain it to a kid.  It’s somewhere 
between magic and a trick pool shot. 

 

Jack Aubert 

 

 

From: sundial  On Behalf Of R. Hooijenga
Sent: Saturday, April 3, 2021 3:47 PM
To: sundial@uni-koeln.de
Subject: RE: Is this an educational sundial, or a 'NON-dial'?

 

For this kind of instrument, I personally like to use the term 'Undial'. 

So far, it didn't catch on, however - pity! 😊

 

Good Easter,

Rudolf Hooijenga 52 30 N 4 40 E

 

-Oorspronkelijk bericht-

Van: sundial mailto:sundial-boun...@uni-koeln.de> > Namens Linda Reid

Verzonden: zaterdag 3 april 2021 20:04

Aan: sundial@uni-koeln.de <mailto:sundial@uni-koeln.de> 

Onderwerp: Is this an educational sundial, or a 'NON-dial'?

 

 

[...]  but looking at the illustration on the front cover, it seems to be a 
'NON-dial'!

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RE: Strange sundial in China

[Jack Aubert]

 

 

Moslem sundials were generally constructed with a view to determining the 
correct time for prayers rather than dividing the day into equal parts.  Most 
of the prayer times are easily determined by observation with minor refinements 
like inability to distinguish a black thread from a white one at sunset.  The 
prayer times are: 

 

Fajr - dawn

Dhuhr - midday

Asr - mid-afternoon

Maghrib - sunset

Isha - night

 

The two times that present difficulties, and where the sun's shadow comes into 
play, are Dhur, midday and Asr, mid-afternoon.  

Asr is particularly problematic because it is defined by a rule -- and there 
are variants depending on the sect -- relating the length of an object's shadow 
and the length of its shadow at noon.  It is harder to estimate than Dhur if 
only because at Asr the length of the objects shadow at midday is no longer 
directly observable.   Asr is usually marked clearly on islamic dials like the 
ones in Turkey.  The other thing of interest is sometimes how much daylight is 
still left before Maghrib   

 

The photo seems to show a stone tablet propped up on blocks of some sort inside 
the building.  Is there any indication of how the sundial -- if it is one -- 
was originally situated?  Horizontal or vertical?  I have actually visited the 
mosque in Xian many years ago but did not see a dial.  If it had been 
accompanied by a plaque I think I would have certainly noticed it.  I did, of 
course, see the unremarkable dial in the Forbidden City, which looks like an 
import from the West,  and have always wondered why the Chinese did not seem to 
have felt any need for sundials.  

 

The layout of the holes with widely and closely spaced marks suggests that it 
may have been a variation on a polar dial designed to start at midday. For most 
latitudes a vertical object casts a shadow at noon and a normal polar dial 
would not be appropriate, since there is a requirement for a midday shadow 
length.  This might have been a “horizontal- polar” dial.  The first set of 
single marks might have been the length of a dhur shadow at different months 
and the second set of (double) marks might have been Asr for different months.  
Or maybe it was designed for a movable gnomon.  

 

This is all completely speculative with no serious model to figure out if it is 
even plausible.  If anybody is going to be visiting Xian it would be worthwhile 
to take some photos that could be used to count the marks more clearly and 
figure out their spacing.  With accurate measurements, it may be possible to 
figure out.  Or maybe there is somebody in China who has already figured it 
out.  

 

Jack Aubert

 

From: sundial  On Behalf Of pol...@sterrenwacht.eu
Sent: Tuesday, January 5, 2021 9:23 AM
To: sundial@uni-koeln.de
Subject: Strange sundial in China

 

Hi group,

I saw this sundial in the Xi'an Mosque in China. Can anyone tell me how this 
sundial worked?

 

Clear skies,  🔭
Gerard van den Braak
 <http://www.sterrenwacht.eu/> www.sterrenwacht.eu
 <http://www.zonnewijzers-nederland.nl> www.zonnewijzers-nederland.nl

 

 

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RE: Time problem

[Jack Aubert]

I have been thinking about this problem but I may not be understanding it
correctly.  I think you want to find out what time sunrise was on September
23 in 1392.  Because of the change from Julian to Gregorian dates, this
corresponds to our October 1.  On October 1, a real clock in Milan this year
would not tell quite the same time as a municipal clock in 1392, though.  

 

We can easily correct for daylight saving time.  The second thing to
consider would be the equation of time.  But it has changed very little
between 1329 and now, so sunrise on October 1 1329 in Milan should be almost
the same time as it is now, so if you could transport a modern clock to
Milan in 1329, it would show sunrise at very close to the same time as it
does now.  But this would not necessarily be the case in 1392.  At that
time, clocks would normally not take the equation of time into account at
all.  Since they were not very accurate over an extended period, they would
have had to be adjusted frequently using a sundial.  So the municipal clock
would probably have shown noon at what we would call 12:11.  It is possible
that a clock used by an astronomer might make the adjustment using a
contemporaneous equation of time table (which would have been less accurate
than our calculation) but this seems unlikely.  

 

The other thing to take into account is Milan's longitude.  At 9.11 degrees
East, Milan is six degrees from the 15 degree time zone center, for a clock
offset of 24 minutes.   So a calculation for modern civil time at that
location should include both the longitude and equation of time.  A
calculation of contemporary civil time would obviously not have included a
time zone offset, I think, should not have included the equation of time
either. 

 

It sounds to me as if the programs may be handling the longitude offset, and
possibly the equation of time differently.   

 

Does this make sense?  

 

Jack Aubert  

 

From: sundial  On Behalf Of Ross Sinclair
Caldwell
Sent: Monday, June 29, 2020 2:06 PM
To: Michael Ossipoff 
Cc: sundial list sundials 
Subject: RE: Time problem

 

Yes, but I don't know if any estimation of refraction or diameter would
account for 20 minutes!

 

In any case, the real time is scarcely relevant - they only wanted to say
that it was shortly after sunrise, sufficiently so that the Sun  was
estimated to be clear of the horizon. 

 

The clock they used only matters for the calculation of minutes, which with
a 24-hour clock, however calibrated, would be the same as ours for all
practical purposes.

 

The biographer doesn't give the time in clock time, only minutes after
sunrise. This is why I want to know what that is. The true time of his birth
is absolutely irrelevant; we only need to know what they believed, and
interpreted from that belief. 

 

Ross

  _  

De : Michael Ossipoff mailto:email9648...@gmail.com> >
Envoyé : lundi 29 juin 2020 19:31
À : Ross Sinclair Caldwell mailto:belmu...@hotmail.com> >
Cc : sundial list sundials mailto:sundial@uni-koeln.de> >
Objet : Re: Time problem 

 

Okay, but there's the inaccuracy of the clocks in those days, and the
importance of that would depend on how they determined Sunrise. I guess they
set the clocks by sundial or noon-mark, but, as you said, it depends on how
often they set them.

 

Anyway, the difference between the NOAA Sunrise-time, and the one calculated
by the planetarium-programs could result from the planetarium-programs not
taking into account the changes in orbit or obliquity.  I'd expect that the
NOAA figure would be more reliable.

 

Sunrise & Sunset times are usually calculated using a standard value for
atmospheric refraction at the horizon. The usual assumption is that the
refraction is 34 minutes and that the Sun's apparent semi-diameter is 16
minutes. Maybe NOAA used a calculated semi-diameter instead of the standard
16 minutes.

 

You don't have sufficiently reliably accurate information for a horoscope
accurate to the minute, and another reason for that is that unusual
atmospheric refractivity could change Sunrise-time by minutes.

 

Michael

 

 

 

On Mon, Jun 29, 2020 at 1:09 PM Ross Sinclair Caldwell mailto:belmu...@hotmail.com> > wrote:

 

Hi Michael,

 

Also, when they said that he was born a certain number of minutes after
Sunrise, how did they determine that? By judging when it seemed to be
Sunrise, when the Sun appeared over the trees, mountains or buildings, or by
calculating Sunrise-time based on a 14th century estimate of Milan's
longiitude?  And were they minutes of equal-hours time, or of
temporary-hours time?

I can answer some of those questions with reasonable certainty. 

 

For minutes, they used an equal-hour 24 hour clock, beginning a half-hour
after sunset the previous day. That is, the clock would strike "1" at, say,
at our 20:45 on that particular day (30 September Gregorian). Of course it
was const

RE: Advice sought re:transparent sundial design

[Jack Aubert]

I think it may be difficult to get a good visible shadow on glass viewed from 
outside.  Stained glass dials work nicely from a darkened room inside. There is 
also the question of finding an appropriate type of paint that will stand up to 
the UV light.  

It may be more difficult to handle the mechanical aspects of this project than 
the actual design of the dial.  Has John Carmichael been able to comment?  He 
is the stained glass expert.  

 

Jack Aubert  

  

 

 

From: sundial  On Behalf Of Michael Ossipoff
Sent: Wednesday, April 22, 2020 7:19 PM
To: Steve Lelievre 
Cc: Alon Gan ; sundial list 
Subject: Re: Advice sought re:transparent sundial design

 

 

Steve--

 

Yes, undeniably the co-Italian hours have more practical use than Babylonian 
hours, as do the Temporary Hours that used to be standard before clocks came 
into use.  

 

For outdoor work like agriculture, or anything for which candle-light wasn't 
sufficient, of course it mattered very much how many hours were left before 
sunset(co-Italian), or  what percentage of the day remained (Temporary-Hours). 
If you've plowed 1/3 of the field that needs plowing today, then it's desirable 
that not more than 1/3 of the day has elapsed.

 

But I wouldn't choose Temporary Hours, because now the matter of how much of 
the day is gone seems like a negative thing to remind oneself of, and not the 
right way to regard the day or the time.  Maybe that's why you don't like 
Babylonian Hours.

 

What I like about Babylonian Hours is that it tells how young the day is, early 
in the morning. That's why I'd include it.

 

Of course, with both Babylonian and co-Italian Hours, one could determine 
Temporary hours by:

 

T = B/(B+CI)

 

...where T = Temporary

 B = Babylonian

 CI = co-Italian

 

Michael Ossipoff

 

Aprilis 23rd, 2020

Taurus 5th

18 Th

 

 

On Wed, Apr 22, 2020 at 3:00 PM Steve Lelievre mailto:steve.lelievre.can...@gmail.com> > wrote:

Michael,

For sure.

I simply ignored the possibility of Babylonian Hours because I 
personally don't think they have much practical use (to the extent that 
any sundial has practical use these days). For a dial showing hours to 
sunset, on the other hand, I do see some hint of practical use. It will 
tell me if I have time to mow the lawn or finish painting the fence 
before it gets dark, and so on. As well, for observers of some 
religions, a sunset dial could be used to know approximately how much 
time is left until, for example, the Sabbath starts or until a daytime 
fast can be broken.

Steve





On 2020-04-22 5:52 a.m., Michael Ossipoff wrote:
> Because the dial is a translucent-double one, with gnomons on both 
> sides of the dial-plate, it would tell time all day, and so it could 
> give Babylonian-hours in addition to co-Italian hours.
>
> On a single dial, with everything on the same dial-face, it would 
> avoid clutter to show Babylonian hours only in the morning, and 
> co-Italian hours only in the evening. But, with the very wide hole in 
> the wall, there's easily room for 3 dials, with one exclusively for 
> Babylonian and co-Italian, and so it wouldn't be cluttered to show 
> both for all day.

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RE: Can a sundial disprove Flat Earth?

[Jack Aubert]

I am not the first to observe that you can pick any arbitrary spot and declare 
it to be the center of the universe.  I frequently argue that there is nothing 
wrong with adopting a geocentric view for the purpose of understanding what we 
see happen in the sky.  It is not actually “wrong”, even in an absolute sense.  
It all depends on what you are want to do.  

 

I was also interested to learn that the church did not try to prevent 
astronomers from using a heliocentric system, which makes astronomical 
predictions much more accurate and simplifies the calculation, as long as the 
earth was still central for theological purposes.  

 

As for the flat-earthers, I have always assumed that they just enjoy the idea 
of pretending to believe something obviously absurd.  Or maybe it is fun to 
actually believe something that contradicts all the physical evidence to the 
contrary.  OTOH, I have come to see that there are a lot of politicians and 
self-declared economists who seem to do the same thing.   

 

Jack

 

From: sundial  On Behalf Of Roger
Sent: Monday, June 17, 2019 11:27 AM
To: Ruud Hooijenga ; kool...@dickkoolish.com; 
sundial@uni-koeln.de
Subject: RE: Can a sundial disprove Flat Earth?

 

A better question is how could you show before telescopes were invented that 
the earth orbits the sun rather than the sun orbiting the earth. We all observe 
that the sun, moon and stars rise and set. Sundial design is the same for 
geocentric and heliocentric systems.

 

Regards, Roger Bailey

Global location: N 48.6°, W 123.4°

 

From: Ruud Hooijenga  
Sent: June 17, 2019 7:22 AM
To: kool...@dickkoolish.com  ; 
sundial@uni-koeln.de  
Subject: Re: Can a sundial disprove Flat Earth?

 

No, that was not a proof of the globe; just a measurement of its size, assuming 
the globe. A small, close sun over a flat earth could give the same result for 
the two locations.

However, several other observations had already proved the globe. 
And you could repeat the Eratosthenes experiment in more than two places, so 
that the flat earth/local sun assumption would have to be discarded.

However, to a dedicated flerfer this will prove nothing, because everything is 
a NASA hoax (it was even in Eratosthenes' time, apparently). 
It's no use wrestling a pig - it will only get you dirty, and the pig enjoys it.

Rudolf

52-30 N 4-40 E

Op 17 juni 2019 om 16:04 schreef kool...@dickkoolish.com 
 : 

Didn't Eratosthenes show that the earth was round by measuring the diameter?

 

 


 

 

Virus-free.  

 www.avg.com 

 

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RE: dischrony

[Jack Aubert]

Yes, I agree that in English the best word would be some kind of "offset"
most likely for local longitude.   Offset has  near synonyms like
"displacement" or "correction."  But it is appropriate here because but it
generally implies either side-to-side or quantitative movement.  It also
implies compensation for something.  It can also be used for monetary
adjustments.  

But I was struck  by "dischrony."   My own version of this term is
dyschromia/dyschromic.   I came up with from dyslexic/dyslesia to describe a
quasi-medical derangement that I suffer from.  

It means a congenital inability to remember dates and times correctly.  If
you tell me a meeting is at  2:30 on March 3,  I will probably remember 1:30
on March 2 or maybe 3:30 on March 1.   I live in fear of being late for
meetings or appointments (or missing them entirely) so I usually end up
being the first person to arrive.  But this is only because I now rely on my
Iphone.  I enter everything carefully  into my phone using, 24 hour
notation, and check it compulsively before I think I may have to be
somewhere.   The time my brain remembers on its own is almost always wrong:
I once showed up for an (thankfully unimportant) group meeting an hour
early, a day late but a week early.  (Sunday at 2:00 PM for a meeting the
following Saturday at 3:00 PM.)   That was before I had a PDA or an Iphone.


Jack Aubert




-Original Message-
From: sundial  On Behalf Of Frank King
Sent: Tuesday, March 12, 2019 8:03 AM
To: fabio.sav...@nonvedolora.it
Cc: sundial@uni-koeln.de
Subject: Re: dischrony

Dear Fabio,

An interesting message...

> In Italy some sundials show the
> written 'costante locale'...

I find Italian gnomonic vocabulary great fun.  There are technical terms
which sound very good in Italian but sound very odd when directly translated
into English.

I especially enjoy 'Foro gnomonico' and
'Meridiana a camera oscura'.

I share your dislike of 'costante locale'.
This could be interpreted in many ways.
Is it the height above sea level or the
local latitude or something else?

In English I often use the word 'offset'
and this can be 'an angular offset' or
'a time offset' or 'a displacement offset'
and for 'costante locale' I would usually
write:

the local longitude offset

It helps that in England, the local
reference meridian is Greenwich but
to be more precise I would write:

  the longitude offset from the
  reference meridian for the local
  time zone

>From where I am sitting:

  My longitude offset (from the
  Greenwich meridian) is one-eighth
  of a degree east or 30 seconds of
  time.

'Offset' is used for angles, time
or distance.

Frank

Frank King
Cambridge, U.K.


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RE: More Sun

[Jack Aubert]

Corrected HTTP link:

https://www.outsideonline.com/2380751/sunscreen-sun-exposure-skin-cancer-sci
ence?utm_medium=social&utm_source=email&utm_campaign=onsiteshare

Jack Aubert

-Original Message-
From: sundial  On Behalf Of Jack Aubert
Sent: Saturday, January 12, 2019 4:15 PM
To: 'Kevin Karney' ; 'sundial list' 
Subject: More Sun

And on a related note, slightly off-topic, here is an article that suggests
the medical advice to avoid the sun may completely wrong:


... which reinforces my skepticism about pretty much all medical/health
advice that is published in the press:  "Studies show that..."

Jack

-Original Message-
From: sundial  On Behalf Of Kevin Karney via
sundial
Sent: Saturday, January 12, 2019 1:28 PM
To: Stanislav Putowsky via sundial 
Subject: 

Diese Nachricht wurde eingewickelt um DMARC-kompatibel zu sein. Die
eigentliche Nachricht steht dadurch in einem Anhang.

This message was wrapped to be DMARC compliant. The actual message text is
therefore in an attachment.

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More Sun

[Jack Aubert]

And on a related note, slightly off-topic, here is an article that suggests
the medical advice to avoid the sun may completely wrong:

https://www.outsideonline.com/2380751/sunscreen-sun-exposure-skin-cancer-sci
ence?utm_medium=social&utm_source=email&utm_campaign=onsiteshare

... which reinforces my skepticism about pretty much all medical/health
advice that is published in the press:  "Studies show that..."

Jack

-Original Message-
From: sundial  On Behalf Of Kevin Karney via
sundial
Sent: Saturday, January 12, 2019 1:28 PM
To: Stanislav Putowsky via sundial 
Subject: 

Diese Nachricht wurde eingewickelt um DMARC-kompatibel zu sein. Die
eigentliche Nachricht steht dadurch in einem Anhang.

This message was wrapped to be DMARC compliant. The actual message text is
therefore in an attachment.

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RE: Equinox Analemma

[Jack Aubert]

I had the same reaction.  I think the NASA page is simply mistaken.  

Either that or the image was edited to make it vertical.  

 

Jack Aubert

 

From: sundial  On Behalf Of Bill Gottesman
Sent: Sunday, September 23, 2018 10:59 AM
To: Robert Terwilliger 
Cc: Sundials List 
Subject: Re: Equinox Analemma

 

The NASA page says the photos were taken at 4PM, but it sure looks like they 
were taken at mean solar noon (because the analemma is vertical).  Does anyone 
have an explanation for this?

 

-Bill

 

On Sun, Sep 23, 2018 at 10:38 AM Robert Terwilliger mailto:b...@twigsdigs.com> > wrote:

Astronomy Picture of the Day

 

https://apod.nasa.gov/apod/ap180923.html

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RE: EU backs ending Daylight Saving Time

[Jack Aubert]

In Paris, and I believe all of France, lunchtime is always at 1:00 PM.
Solar moon (more or less).  

Jack

-Original Message-
From: sundial  On Behalf Of Frank King
Sent: Friday, August 31, 2018 10:32 AM
To: Steve Lelievre 
Cc: Sundial List 
Subject: Re: EU backs ending Daylight Saving Time

Dear Steve,

Your subject line is ambiguous...

  EU backs ending Daylight Saving Time

Does this mean:

   A: The EU wants to give up DST?

or:

   B: The EU wants DST not to end?

The report suggests the latter:

  Commission President Jean-Claude Juncker
  said millions "believe that in future,
  summer time should be year-round, and
  that's what will happen".

If you look at the Greenwich meridian
you will see that it has a longer run
through France than through the U.K.

This suggests, to me(!), that both
countries should be on GMT.

As it happens, France was on GMT until
the Germans inflicted Nazi time on them
during the war and they have never
switched back.

In my book, France is already
on Summer Time in Winter.  It is
on Double Summer Time in Summer.

OK, here is an anecdote...

I stayed on an extra day after the
NASS conference and, at breakfast
on the Monday, I had a fascinating
exchange with the friendly waitress
who had served me for the better
part of a week:

  Waitress: were you with the
  Shengal Group?

  Me: Er, the what group?

  W: Ah, how do you pronounce it?
  The delegates who were in the
  Forbes Room?

  Me: Oh, that was the sundial
  group.

  W: Is that a branch of
  Scientology?

  Me: I know very little about
  Scientology but I don't think
  there were any Scientologists
  in the Sundial group.

  W: What did you discuss?

  Me: [Using knife as a gnomon
  and attempting to appear as
  unthreatening as possible!]
  You see this shadow on the
  table?  Well you can watch
  it move round and deduce the
  time of day.

  W: Ah.  It's to do with the
  SUN then?

  Me: Yes, you've got it!

  W: What do you think of
  Daylight Saving Time?

  Me: [I recounted the story
  of the Native American who
  said "Only a white man could
  believe that by cutting a
  foot off one end of a blanket
  and stitching it to the other
  end you get a longer blanket.]

  W: Gee.  I like that.  My
  husband is a pilot and he
  keeps telling everyone that
  Daylight Saving Time is a
  load of Bullshit.

  Me: You have an admirable
  husband.

My guess is that, in the UK, about
60% of the population would feel
they have come across the word
"sundial" though most would think
it was just a garden ornament:
some kind of statue, or bird bath
or even a garden gnomn!

With this sample of one, I am
minded to guess that the U.S.
percentage is lower!

We must all do our bit to educate
the masses!

Very best wishes

Frank

Frank H. King
Cambridge, U.K.

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RE: Is this sundial business 'genuine', or not?

[Jack Aubert]

It is widely unknown – or forgotten – that even the Roman Catholic Church did 
not actually reject the Copernican thesis outright.  It depended on what it the 
model was to be used for.  Astronomers were not prevented from using the 
heliocentric model for the purpose of calculating the course of the planets 
because it made the calculations enormously easier and more accurate.  The 
geocentric model was only required for theological purposes.  And, in fact, 
both perspectives are perfectly valid for their chosen purpose.  Any point in 
the universe can be arbitrarily selected as the fixed spot with respect to 
which everything else moves if you don’t need to calculate and predict their 
paths.  

 

Unfortunately children are not “permitted” to imagine the earth as the central 
fixed point.  Everybody knows that the earth revolves around the sun.  The sun 
does not revolve around the earth, silly!.  

 

But it is almost impossible to understand the daily motion of the stars, the 
sun and the seasons without adopting a geocentric perspective. 

 

Eppur se muove!

 

Jack Aubert

 



 

 

 

From: Steve Lelievre  
Sent: Thursday, July 19, 2018 11:39 AM
To: sundial@uni-koeln.de
Cc: Jack Aubert 
Subject: Re: Is this sundial business 'genuine', or not?

 


This reminds of an interview I read somewhere, with a former RAF instructor who 
taught survival navigation techniques for downed fighter pilots - no GPS or 
compass, just sun and stars. He said that one of frustrating parts of his job 
was that with every new class he had to un-teach the idea drummed into them at 
school that the Earth goes around the Sun, and not the other way round. The 
requisite skills came much faster to pilots who accepted the correction.

Steve

On 2018-07-18 1:51 PM, Jack Aubert wrote:



 

If I were doing the curriculum I would reintroduce the geocentric view of the 
solar system to complement the Copernican view.   

 

Jack

 

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RE: Is this sundial business 'genuine', or not?

[Jack Aubert]

HI Roger,

 

The layout is not the problem.  That’s relatively easy.  The problem is keeping 
an image of the relationship between the three dimensional sky and two 
dimensional earth in your head so that it makes intuitive sense, particularly 
if you are just a kid.

 

We are dealing with a projection of the equatorial circle of an armillary 
sphere onto the ground which becomes an ellipse with hour points along it.  The 
projection of the axial gnomon is just a line and doesn’t work for telling 
time.  Instead, we have to locate a point on that line, which could be its end. 
 That point has to move back and forth along the axis throughout the year: your 
magical pencil, which is able to shorten and lengthen as needed.  Why do we 
have to do that?  Well that’s another story we will skip for today.   But when 
we are done, we throw away the circle and the magic pencil and are left with an 
ellipse on the ground plus a stick (or a person’s head ) that has to move north 
and south depending on the date according to a secret formula.   

 

So first you have to imagine the polar dial as a hoop, translate it to an 
elliptical projection, and then imagine a magic pencil that projects its tip 
onto the ellipse.   It is not so easy hold all the construction imagery in your 
head so that you can relate it all back to the celestial sphere with the sun on 
it.  Not only that, but they never told you about the celestial sphere in the 
first place.  They probably told you that the sun is at the center of the solar 
system and the earth rotates and orbits around it.Good luck imagining how 
that explains what you see in the sky every day.

 

If I were doing the curriculum I would reintroduce the geocentric view of the 
solar system to complement the Copernican view.   

 

Jack

 

 

   

 

 

 

From: Roger  
Sent: Tuesday, July 17, 2018 7:32 PM
To: Jack Aubert ; 'Michael Ossipoff' 
; 'sundial list' 
Subject: RE: Is this sundial business 'genuine', or not?

 

Hi Jack and Michael,

 

I don’t agree. The concept is very simple. Perhaps you have had bad teachers. 
One of my presentations at the upcoming conference is a purely grapghical 
method of designing an analemmatic sundial. No trig, not even geometry other 
than the Greek’s ruler and string or a simple math set with ruler, protractor 
and a compass.  From this graphical technique comes a whole new concept by  
Chris Lusby Taylor for seasonal makers that I will describe at the conference 
next month.

 

To demonstrate the simple concepts for analemmatic sundials, start with this 
experiment as a class activity, hands on and interactive. Cut out a circle of 
cardboard. Stick a pencil through the center at a right angle to the disc. Hold 
it with the pencil vertical. Look straight down on the disc, a circle true 
size. Hour angles drawn every 15° would also be true angles. The pencil is seen 
as a point. Now physically drop the disc and pencil onto a horizontal table. 
Get down to view across the table and turn the disc to see it on edge. It will 
be seen as a true length straight line equal to the diameter of the circle. The 
pencil will also be seen a true length line. If you chose the right length of 
pencil, the pencil will make an angle to the horizontal equal to your latitude. 
The disc will make an angle to the co-latitude.  Now get up and look straight 
down on the disc and pencil on the table. The disc will be seen as an ellipse 
and the pencil as a shorter line as neither disc or pencil are true length. 
Look at it straight down from above and mark the point on the desk that is 
directly under the end of the hour mark on the disk starting with the disc 
turned to the starting point noon being directly under the pencil. These points 
define. the hour ellipse for an analemmatic sundial.

 

Next the enigmatic date line. Consider the sun shining down at noon at any day 
of the year onto the pencil through the disc on the table. The sun shines down 
on the pencil and there is a unique point on the pencil each day where the sun 
at noon shines directly onto the rim of the disc. At the summer solstice the 
sun is high in the sky. The angle of the suns ray down to the disc rim is at an 
angle of 23.5° to the disc. At the winter solstice the angle is -23.5 ° On the 
spring and fall equinox the angle is 0°. Every day has a different angle, the 
solar declination for that day. Now you could switch to ruler and protractor 
marking on paper right angle  triangles with the base equal to the disc radius. 
Measure angles from the base point up at the chosen declination angle and draw 
a line at that angle to the line at right angles to the other end of the base 
line for the declination points for the chosen dates. Now draw a line for the 
horizon at an angle to the disc base line equal the latitude. Draw lines 
perpendicular to the horizon line to the chosen declination date points.  The 
points on the horizon

RE: Is this sundial business 'genuine', or not?

[Jack Aubert]

I very much agree with this.  In fact, at the risk of sounding stupid, I have 
to confess that I don’t have an intuitive grasp of how an analemmatic dial 
works.  Yes, I have at various times gone through the explanation, but it does 
not stick in any way that I can mentally attach to the plane of the earth’s 
surface and the motion of the celestial sphere.  I know I could review the 
geometry and remember it if I tried but agree that the geometrical projections 
involved are beyond the grasp of almost all children and almost all adults. 
 

 

Jack

 

From: sundial  On Behalf Of Michael Ossipoff
Sent: Tuesday, July 17, 2018 12:29 AM
To: sundial list 
Subject: Re: Is this sundial business 'genuine', or not?

 

 

To continue something that I started before:

 

The derivation of the construction of the Analemmatic could be explained to 
anyone, with 3 lesson-sessions, over 3 days.

 

Yes, an Analemmatic Dial could be educational, when it gives people incentive 
to study, read about or listen to the dial's derivation, is 
construction-explanation.

 

So the Analemmatic with its trigonometry requirement, could be useful, helpful, 
educational, at a highschool (secondary school), college or university.

 

...but not at an elementary-school (primary school), okay? How many 
elementary-school kids would want to listen to that explanation?

 

Will someone tell me how an Analemmatic Dial would be educational at an 
elementary-school?

 

There was a line in the movie "Fatal Attraction", in which the mother is 
considering taking their primary-school child with her, when she goes to visit 
her father (probably for the purpose of looking at a nearby house that they're 
considering purchasing).  The Father questions whether the child should miss 
school by going on the visit. The mother replies, "What's she going to miss, 
trigonometry?"

 

What dial's explanation would be of interest to an elementary-school audience?  
Any of the Central-Gnomon Equatorial dials, such as the Disk-Equatorial, 
Band-Equatorial and Cylinder-Equatorial (with central gnomon). Their showing of 
Solar Time is completely direct.

 

The Horizontal Dial's explanation is brief, and might very well be acceptable, 
of interest, to many elementary-school students,. 

 

Vertical or Reclining, but non-Declining, Flat Dials might not be significantly 
more difficult to explain, since they're just horizontal dials for a different 
latitude.   ...demonstrable with a globe.

 

So, if some of the kids are little vandals, you could install a South Vertical 
Dial, bracket-mounted high on a wall (or flat-mounted on a south-wall).

 

The Circumference-Aperture Cylindrical Equatorial Dial would be easier to 
explain than the Analemmatic, but its explanation might still only be of 
interest to highschool students.

 

...because of its geometric diagram, with its triangles, with letter-labeled 
angles, and the equations relating its angles--and the making of new equations 
by doing the same thing to both sides of an equation, or adding or subtracting 
two equations, or substituting one equal thing for another in an 
equation--sounds like a secondary-school topic.

 

Well, probably pre-secondary school (junior-high, middle-school) kids too, 
because when I was in junior-high, our general-math class introduced 
equation-solving.

 

...but I don't know if there would be much interest in it in primary-school. I 
don't know if I'd be brave enough to get up in front of a class and start 
explaining it there.

 

Anyway, so I'm just saying, only offer dials whose construction derivation 
explanation would be of interest to the people to whom you're offering the 
dial. 

 

By the way, I say the same thing about map-projections. For a first world-map 
projection, for a wall or a book-page, in primary-school, I suggest  Apianus 
II, an elliptical pseudocylindrical map with equidistant parallels. 

 

(A pseudocylindrical map has parallels that are mutually-parallel straight 
lines, each one uniformly divided by the meridians (In other words, the scale 
along each parallel is uniform.) ).

 

The equator and central meridian have the same scale, and the map is twice as 
wide as high.

 

If that scale along the parallels is the same along each parallel, and is the 
same as the uniform scale along the central meridian, that's the Sinusoidal 
Projection. It's useful, but many people feel that it looks awful.  It's that 
roughly diamond-shaped world map that you might have seen. Apianus II has a 
pleasing globe-similar elliptical shape.

 

Michael Ossipoff

 

 

 

 

 

 

On Thu, Jul 12, 2018 at 8:47 PM, Michael Ossipoff mailto:email9648...@gmail.com> > wrote:

If I may correct a small error in something that I said:

 

I said:

 

 

That's easily remedied  by having additional apertures at the 6 am & pm 
positions, with a few separate special hour-lines for use with those 
aperatures.  I'd make those 6-o'clock apertures double, to make them 
easily

RE: blank subject line

[Jack Aubert]

Sorry for the non-sundial spam.  

 

This is just a test to see if my mail server, which I run, is DMARC compliant.  

It should pass the SPF test but I may have to install DKIM 

 

Jack Aubert

 

From: sundial  On Behalf Of Fred Sawyer
Sent: Tuesday, May 22, 2018 2:51 PM
To: Doug Bateman 
Cc: Sundial List 
Subject: Re: blank subject line

 

Doug

 

The irony is that your email arrived without a subject line.  Take note of 
Steve Lelievre's earlier email.

 

When emails are not DMARC compliant the system wraps them into another email 
and sends it via sundial with no subject.

 

Fred

 

 

 

On Tue, May 22, 2018, 2:01 PM Douglas Bateman via sundial mailto:sundial@uni-koeln.de> > wrote:

Diese Nachricht wurde eingewickelt um DMARC-kompatibel zu sein. Die
eigentliche Nachricht steht dadurch in einem Anhang.

This message was wrapped to be DMARC compliant. The actual message
text is therefore in an attachment.


-- Forwarded message --
From: Douglas Bateman mailto:douglas.bate...@btinternet.com> >
To: Willy Leenders mailto:willy.leend...@telenet.be> >
Cc: Eric Daled mailto:eric.da...@telenet.be> >, Sundial 
list mailto:sundial@uni-koeln.de> >
Bcc: 
Date: Tue, 22 May 2018 19:01:26 +0100
Subject: Re: Blank subject line
Regardless of the technical stuff and suspicion, I regard a subject line as a 
simple courtesy!

Best wishes, Doug

> On 22 May 2018, at 18:02, Willy Leenders  <mailto:willy.leend...@telenet.be> > wrote:
> 
> Why that suspicion?
> The mention of a subject does not guarantee reliability and the absence of a 
> subject is not a sign of unreliability.
> 
> Willy Leenders
> 
> 
> 
> Op 22-mei-2018, om 17:00 heeft Eric Daled het volgende geschreven:
> 
>> And I agree also : I always delete such messages.
>> 
>> Eric
>> 
>> 
>> -Oorspronkelijk bericht- From: Roger W. Sinnott Sent: Tuesday, May 
>> 22, 2018 4:33 PM To: sundial@uni-koeln.de <mailto:sundial@uni-koeln.de>  
>> Subject: RE: Blank subject line 
>> I agree with Helmut!  
>> When I see a blank subject line, I become suspicious and often just delete
>> the message without opening it.
>> 
>> Roger
>> 
>> 
>> -Original Message-
>> From: sundial [mailto:sundial-boun...@uni-koeln.de 
>> <mailto:sundial-boun...@uni-koeln.de> ] On Behalf Of Helmut
>> Haase
>> Sent: Tuesday, May 22, 2018 10:11 AM
>> To: sundial@uni-koeln.de <mailto:sundial@uni-koeln.de> 
>> Subject: Blank subject line
>> 
>> Hallo gnomonicist,
>> It seems to become a trend here to send mails without subject information.
>> 
>> Is it difficult to write a subject line?
>> 
>> Regards
>> 
>> Helmut Haase
>> 
>> 
>> 
>> ---
>> https://lists.uni-koeln.de/mailman/listinfo/sundial
>> 
>> ---
>> https://lists.uni-koeln.de/mailman/listinfo/sundial
>> 
>> ---
>> https://lists.uni-koeln.de/mailman/listinfo/sundial
>> 
> 
> 
> 
> Bezoek mijn webstek met alle zonnewijzers in Limburg (Vlaanderen) en een 
> rubriek (zonne)wijzerweetjes: http://www.wijzerweb.be
> 
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
> 

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RE: Inquiry

[Jack Aubert]

Steve,

I know that the first statement is accurate.  One reference is a paper
written by Andrée de Gotteland, now deceased, in Revue #27 of the
Association Française des Amateurs d'Horlogerie Ancienne.   Mme Gotteland
quotes a newspaper (Mercure de France) to the effect that clockmakers are
exposed to criticism by the public that their clocks are not accurate
because they disagree with the local sundial which tells Civil (legal) time.
The association of clockmakers apparently adopted the motto:  "Solis
mendaces arguit horas" (the Sun's hours are deceptive).  

This paper was also cited in Christopher Daniel's excellent and definitive
monograph on the Equation of Time and invention of the Analemma, published
in the BSS volume 17.

Jack Aubert 



-Original Message-
From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Steve
Lelievre
Sent: Friday, April 21, 2017 3:45 PM
To: sundial@uni-koeln.de
Subject: Inquiry

Hi,

I've got a two part inquiry from a third party:

1. Is it true that Louis XIV issued some kind of edict that all clocks
manufactured in France were to be Equation Clocks (that is, clocks that
showed solar time through a mechanical Equation of Time 'reversal' 
adjustment). References sought.

2. Can anyone confirm that throughout the 19th centuary (and perhaps into
the early 20th centuary?), the French railways system used heliochronometers
installed at each station for daily calibration of station clocks? Again,
references sought.

Thanks,
Steve


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RE: Looking for minutes and seconds correction for whole year for Equation of Time plaque

[Jack Aubert]

HI Simon,

 

I like to use the “time of solar transit” version of the EOT from your 
spreadsheet because I can never remember with any confidence if I am correcting 
the watch or the dial.

 

Jack Aubert

 

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Simon Wheaton 
Smith
Sent: Wednesday, January 25, 2017 8:08 PM
To: Kenneth R clark 
Cc: sundial@uni-koeln.de
Subject: Re: Looking for minutes and seconds correction for whole year for 
Equation of Time plaque

 

Last email from me today...

 

here is the 4 year EOT from my main book

 

Simon

 

On Wed, Jan 25, 2017 at 5:21 PM, Kenneth R clark mailto:krcl...@embarqmail.com> > wrote:

I had an error message from AOL Sorry for no subject line and my files were not 
sent.

Let me retry with this account.

 

Hi everyone,

 

 I am working on my Equation of Time plaque for my aluminum cross sundial.  
All the instructions and graphics and EQT will be on an 8 ½” diameter ½” 
aluminum plate.  I do not want to use the standard graph found on many sundials 
but instead a chart for the whole year, mins and secs, to add or subtract total 
correction to get watch time.  I do not have much room for detailed 
instructions.

 

 I looked at difference sources for the chart and would like to verify the 
most accurate times to use the four year leap year cycle for a church at 
40.1526N, 76.6038W.   I have looked at the Solar Noon calculator, Sonne and 
Shadows-(cannot input decimal degrees?)  Are there other sources or spreadsheet 
programs?

 

 I like to convey that sundials are accurate.  I envision that a person 
will wait till the shadow is on a line and the person will know what time it is 
suppose to be even though this type of sundial may not be design for precision.

 

 I made a quick drawing.  There will be some type of sun image at the top 
and a logo at the bottom for the location.  The chart in the center is from 
another project that I did just to see how it would look and if the printing is 
large enough to read.  I would have to change the inputs to standard time for 
the whole year.  I have also attached a picture of the sundial.

 

 I just want to know if I am using the right times and would appreciate any 
comments or suggestions.

 

Thanks very much

 

Ken Clark   

Elizabethtown, 
PA


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-- 

Simon Wheaton-Smith

www.illustratingshadows.com <http://www.illustratingshadows.com> 

Phoenix, AZ

W 112.1, N 33.5

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RE: An interesting piece of timekeeping

[Jack Aubert]

No, as far as I know, it’s only for Iphone.

 

From: rodwall1...@gmail.com [mailto:rodwall1...@gmail.com] 
Sent: Wednesday, January 18, 2017 12:26 AM
To: Jack Aubert ; 'David Patte ₯' 
; sundial@uni-koeln.de
Subject: Re: An interesting piece of timekeeping

 

Hi Jack,

 

Is this for Android? I couldn't find it.

 

Roderick Wall.

 

- Reply message -----
From: "Jack Aubert" mailto:j...@chezaubert.net> >
To: "'David Patte ₯'" mailto:dpa...@relativedata.com> 
>, mailto:sundial@uni-koeln.de> >
Subject: An interesting piece of timekeeping
Date: Wed, Jan 18, 2017 10:17 AM





The smartphone app has been written.  
 
Look for Chronometer by Emerald Sequoia.  You can easily spend hours exploring 
it.  It consists of fifteen different virtual watches, each one offering a 
different set of temporal and astronomical features.
 
 
 
Jack Aubert
 
 
 
From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of David Patte ?
Sent: Monday, January 16, 2017 10:11 PM
To: sundial@uni-koeln.de <mailto:sundial@uni-koeln.de> 
Subject: Re: An interesting piece of timekeeping
 
 
 
True, but if I can get 125 sponsors of $400 each I can write you a smartphone 
app that has all the same features, looks similiar, and is 10 times more 
accurate - and it will adjust to your local timezone and labelling in 10 
languages to boot :)
 
 
 
 2017-01-16 21:42, J. Tallman wrote:
 
It is not a sundial, but interesting nonetheless:
 
http://www.ablogtowatch.com/vacheron-constantin-les-cabinotiers-celestia-astronomical-grand-complication-3600-watch/
 
It is quite a feast for the eyes, and the mind...and if you have a spare 
million lying around, it could be yours!
 
 
 
Best, 
 
Jim Tallman
Artisan Industrials
 
www.artisanindustrials.com <http://www.artisanindustrials.com>  
<http://www.artisanindustrials.com>  
www.spectrasundial.com <http://www.spectrasundial.com>  
<http://www.spectrasundial.com>  
jtall...@artisanindustrials.com <mailto:jtall...@artisanindustrials.com>  
<mailto:jtall...@artisanindustrials.com>  
513-253-5497
 
 
 
 
 
 
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-- 
 
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RE: An interesting piece of timekeeping

[Jack Aubert]

The smartphone app has been written.  

Look for Chronometer by Emerald Sequoia.  You can easily spend hours exploring 
it.  It consists of fifteen different virtual watches, each one offering a 
different set of temporal and astronomical features.

 

Jack Aubert

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of David Patte ?
Sent: Monday, January 16, 2017 10:11 PM
To: sundial@uni-koeln.de
Subject: Re: An interesting piece of timekeeping

 

True, but if I can get 125 sponsors of $400 each I can write you a smartphone 
app that has all the same features, looks similiar, and is 10 times more 
accurate - and it will adjust to your local timezone and labelling in 10 
languages to boot :)



 2017-01-16 21:42, J. Tallman wrote:

It is not a sundial, but interesting nonetheless:

http://www.ablogtowatch.com/vacheron-constantin-les-cabinotiers-celestia-astronomical-grand-complication-3600-watch/

It is quite a feast for the eyes, and the mind...and if you have a spare 
million lying around, it could be yours!



Best, 

Jim Tallman
Artisan Industrials

www.artisanindustrials.com <http://www.artisanindustrials.com>  
www.spectrasundial.com <http://www.spectrasundial.com>  
jtall...@artisanindustrials.com <mailto:jtall...@artisanindustrials.com>  
513-253-5497






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-- 
 
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RE: Photo-etching

[Jack Aubert]

I have been photo-etching sundials following Tony's video for several years
and have written up detailed instructions based on my own experience,
including availability of tools and materials.  
For anybody who wants to have a go at this here is a link to that paper:
https://dl.dropboxusercontent.com/u/86772658/PhotoEtchingDetailedinstruction
s.pdf

Jack

-Original Message-
From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of John
Goodman
Sent: Thursday, September 01, 2016 7:53 AM
To: Sundial List 
Subject: Re: Photo-etching

You can find Tony's BSS photo-etching video on YouTube -
www.youtube.com/watch?v=HkpCCA-hgrc

The same video was posted in two parts back in 2010:

Part 1 - www.youtube.com/watch?v=ML37yRmAsOA
Part 2 - www.youtube.com/watch?v=PAW0q6i7aqg


> On Aug 31, 2016, at 12:34 AM, Wojtek Galinski wrote:
> 
> Hi Tony,
> 
> Thank you for your reference to some old but cheap technologies of 
> importance for our sundial community. I think we would have much more 
> fun
> (?) had you provided us a link to the film (preferably a link that 
> would be accessible also for those who are not yet members of  the 
> British Sundial Society).
> 
> Best regards,
> 
> Wojtek

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RE: Sawyer Dialing Prize 2016 - Bailey Points

[Jack Aubert]

Roger seems to be the only person in the Sundial community who does not call
them "Bailey Points."I think his Canadian modesty.  

 

Jack

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Helmut
Sonderegger
Sent: Saturday, July 30, 2016 8:39 AM
To: sundial@uni-koeln.de
Subject: Re: Sawyer Dialing Prize 2016

 

Dear Roger
my congratulations for the award of the Sawyer Dialing Prize. I think your
idea of two single points as sunrise and sunset marks in analemmatic
sundials is great. I always include them in constructions for analemmatic
sundials and very often I name them "Bailey Points".
Helmut Sonderegger

Am 30.07.2016 um 06:09 schrieb Roger Bailey:

Roger Bailey is pleased to have receive the NASS Sawyer Dialing Prize for
2016. The certificate recognizes Roger for "consistently showing the dialing
community that all you need to know in life can be learned from studying
sundials, and for using that study to advance the theory and practice of
dialing." For details see
http://sundials.org/index.php/features/sawyer-dialing-prize 

 

On receiving the award Roger's presentation was "That is a Good Question".
Here he pointed out that most of his achievements in the art and science of
dialing was sparked by answering good questions, questions like the shadow
lengths or the time and direction of sunrise sunset on analemmatic sundials
or time systems on Islamic sundials. The theme was "Ask and you shall
receive". He remains open to good questions.

 

Roger Bailey

NASS Secretary

Walking Shadow Designs






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-- 
Helmut Sonderegger
www.helson.at  
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RE: Sundial in Risen movie

[Jack Aubert]

He looks like he’s texting something on his Iphone. 

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of John Davis
Sent: Friday, May 06, 2016 3:32 AM
To: Dan-George Uza 
Cc: sundial@uni-koeln.de
Subject: Re: Sundial in Risen movie

 

Hi Dan,

 

Well spotted!  However, neither the horizontal sundial nor the hourglass was 
invented until the Middle Ages. Yet another example of Hollywood making up 
history!

 

John



 

Dr J Davis
Flowton Dials   http://www.flowton-dials.co.uk/



BSS Editor http://sundialsoc.org.uk/publications/the-bss-bulletin/

 


On 6 May 2016, at 07:58, Dan-George Uza mailto:cerculdest...@gmail.com> > wrote:

Hello,

 

I've spotted a horizontal sundial in the new biblical drama film Risen (2016). 
You can see it in different scenes starting about half an hour into the movie. 
It's alongside a hourglass on a desk belonging to Roman tribune Clavius, the 
main character. I'm attaching a screenshot.

 

Dan Uza



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RE: Southern Hemisphere

[Jack Aubert]

I suggest you look at the British Sundial Society piece created by Tony Moss
that shows how different types of sundials work at different places on the
earth's surface. 

 

http://sundialsoc.org.uk/discussions/how-do-sundials-work/

 

At the poles and the equator, sundials have to take different shapes than
the horizontal plate with inclined gnomon you are used to seeing.   In Perth
your gnomon should, indeed, have a 32 degree slope and be parallel to the
earth's axis.  But the hour line numbers are reversed from what they are in
the northern hemisphere.  

 

Jack Aubert

 

 

 

 

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Phil Dorman
Sent: Sunday, November 15, 2015 5:37 PM
To: sundial@uni-koeln.de
Subject: Southern Hemisphere

 

Hi Everyone,

 

I joined this list because I have a specific question which I can't find a
definitive answer to.

 

I want to install a sundial at Perth WA Australia which is pretty close to
32deg South latitude.

>From what I can determine that means the Gnomon should be 32deg above
horizontal.

Or is that just for the Northern Hemisphere ??

 

As I move North in Australia the Latitude number gets Smaller

Eg Latitude of Brisbane QLD (further North) is 27.46deg 

So presumably the Latitude at the Equator would be Zero !

Which would mean a sundial Gnomon at the Equator would be Horizontal ie Flat
on the Ground

Which of course would not work.

And at the South Pole it would be Vertical 90deg from Horizontal and also
would not work since there would be no ground for the shadow to fall on.

 

So. Am I correct to put it at 32deg from Horizontal for Perth WA or not ?

 

Phil Dorman /:~)>

 <http://www.maates.com/> 

Machinery Appreciation & Transport Engineering Society
946 Wattagan Crk Rd
Watagan NSW 2325

0419 501285

 

 

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RE: NASS site down?

[Jack Aubert]

Yes, the server died, but has been resurrected with some replacement hardware.  
It is back up and running now.

 

Jack Aubert

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Bill Gottesman
Sent: Saturday, October 31, 2015 8:07 PM
To: Sundials List 
Subject: NASS site down?

 

Sundials.org is unavailable tonight.  Anyone aware of a problem?

 

-Bill Gottesman

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RE: Romanian reclining sundial

[Jack Aubert]

I agree that it is reasonable design choice to include the longitude 
correction.  In fact, I think I would include longitude correction in anything 
that is not a straight-up north-south or a horizontal dial where the longitude 
correction makes the dial look skewed.  Once the dial is already shifted out of 
a straight-up north-south alignment then the longitude correction doesn’t look 
“funny”.   And at that point, you may as well set it to summer time (AKA 
daylight saving time) since that is in effect for more than half the year 
including the months when people are more likely to be outside looking at a 
sundial.

 

But these are all reasonable design choices where there is plenty of room for 
debate.

 

We (NASS) set up what I call a “nonce dial” a few years ago for an exhibition 
in Washington, DC.  It was adjusted to show local clock time on the day of the 
exhibition incorporating both longitude and EOT for the date… but it was 
designed a few months before the US congress decided to extend daylight saving 
time further into the autumn so it ended up being off by exactly one hour from 
watch time.  We put up a poster that said “Why is your watch wrong?” It was 
interesting to watch the reactions.  Some people immediately knew why; others 
seemed perplexed.  

 

Jack Aubert

 

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Michael 
Ossipoff
Sent: Sunday, October 04, 2015 7:42 AM
To: Willy Leenders; sundial list
Subject: Re: Romanian reclining sundial

 

On Fri, Oct 2, 2015 at 6:12 AM, Willy Leenders  
wrote:

Dan,

 

What I mean is this:

 

1.

Together with the sundial on the roof is given the EOT table.
What can you do with it?

 

Well, you can add the EoT table entry to the time shown on the sundial, to get 
standard time. 

 

As a result of the empirical way of construction on September 1 you can, using 
the EOT table, determine the standard Eastern European Time on other days.

 

On any day, yes.

Of course, that's clear from what the original-poster said.

 

Specifying the length correction you could also determine the true local time

 

Yes, you could get local true solar time by adding or subtracting 4 minutes to 
the sundial's reading for each degree of latitude east or west of the place's 
time-zone's central meridian.

As for the choice of local true solar time, or true solar time at the central 
meridian, both dial-marking systems are frequently, widely, used. Which you use 
is a matter of individual preference.

Either you mark the dial for true solar time at the central meridian, or you 
incorporate the longitude correction in the EoT table. Both methods are popular.
 


2.
To indicate the standard Eastern European Time you have many options: clock, 
cell phone, computer ...

There's no need to a sundial.

 

Sundials have aesthetic value. Though they can often be of practical 
time-telling use, that isn't their only justification.

Yes, a sundial marked in true solar time at the central meridian is, by 
implication, intended or emphasized for practical use.

 

Indicating the true local time is only possible on a sundial.
Let him do it  !

 

Yes, that's one valid preference, one vaild choice. But both choices are valid.

Yes, I personally  like a sundial to give local true solar time, and 
incorporate the longitude-correction in the EoT table. That's how I made my 
pocket-portable tablet-dials.  

Nevertheless it must be accepted that not everyone makes the same choice that 
we make, and that many sundials are marked in true solar time at the central 
meridian.

Michael Ossipoff

 

On Fri, Oct 2, 2015 at 6:12 AM, Willy Leenders  
wrote:

Dan,

 

What I mean is this:

 

1.

Together with the sundial on the roof is given the EOT table.
What can you do with it?

As a result of the empirical way of construction on September 1 you can, using 
the EOT table, determine the standard Eastern European Time on other days.
Specifying the length correction you could also determine the true local time


2.
To indicate the standard Eastern European Time you have many options: clock, 
cell phone, computer ...

There's no need to a sundial.
Indicating the true local time is only possible on a sundial.
Let him do it  !

 

 

Willy Leenders

Hasselt in Flanders (Belgium)

 

Visit my website about the sundials in the province of Limburg (Flanders) with 
a section 'worth knowing about sundials' (mostly in Dutch): 
http://www.wijzerweb.be

 

 

 

 

 

Op 1-okt-2015, om 22:06 heeft Dan-George Uza het volgende geschreven:





Willy,

 

I'm sorry but I did not quite understand your message. The dial is supposed to 
show standard Eastern European Time, not true local time. The longitude 
correction for Bistrita is already built in the hour marks because they were 
empirically drawn according to the watch when EoT was 0. Therefore the 
correction table only deals with variations in Eot.   

 

Dan

 

On T

RE: Romanian reclining sundial

[Jack Aubert]

It is a very attractive dial and a nice way to decorate one’s roof.  But you 
may want to photoshop out what appears to be an unmetered electrical tap 
powering the bar-restaurant across the street.  

 

Jack Aubert.  

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Dan-George Uza
Sent: Thursday, October 01, 2015 3:25 PM
To: sundial@uni-koeln.de
Subject: Romanian reclining sundial

 

Dear group,

 

I am happy to be able to share a picture of the first Romanian reclining 
sundial built recently by Damaschin Berende, a friend from a neighboring town. 
It's made of plywood, it sits on a roof and it features both a EoT correction 
table and interchangeable hour marks for winter time and daylight saving time. 
Reported accuracy is so far around 1:30 min. Direction of gnomon across the 
roof was fixed by taking a plumb bob shadow 

​reading ​

from the base of the gnomon at local noon, the elevation angle was calculated 
according to the latitudine and the hours were marked on the shadow during 
September 1st, when EoT was 0. I especially like the wooden pole etched with 
traditional solar motifs and the rooster on top. You can view more photos here: 

http://cerculdestele.blogspot.ro/2015/10/sine-sole-sileo-ceasul-solar-inclinat.html

 

Please also consider it for the Sundial of the Month on http://sundialatlas.eu 
using ID no. RO23.

 

Regards,

 

​Dan Uza


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RE: due east photos

[Jack Aubert]

Why not?  Richard Feynman argued that that a quantum mechanical particle can
take an infinite number of paths between two points to explain the wave
function.  Or something like that.  I don’t actually understand that stuff
myself. Maybe the direction to Mecca should be a wave function.  

 

https://www.quora.com/What-is-Richard-Feynmans-sum-over-paths-approach-to-qu
antum-mechanics

 

Jack

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Brent
Sent: Thursday, September 24, 2015 5:58 PM
To: Bill Gottesman
Cc: Sundials List
Subject: Re: due east photos

 

"an infinite number of compass directions to Mecca"

allahu akbar!



.

On 9/24/2015 2:39 PM, Bill Gottesman wrote:

Well, if you are going to allow compass directions, then that opens the door
to all loxodromes.  There are an infnite number of loxodromes that connect
two points on a sphere, if you allow loxodrome paths that travel more than
once around the globe!  This gives an infinite number of compass directions
to Mecca. 

 

-Bill

 

On Thu, Sep 24, 2015 at 4:11 PM, Brent  wrote:

I think you can face Mecca from 4 directions:

1. along great circle shortest direction
2. along great circle longest direction
3. along constant compass method shortest direction
4. along constant compass method longest direction

I wonder if it says in Koran to face Mecca in shortest direction?

brent 

 



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RE:

[Jack Aubert]

I have done something similar with etched-engraved dials.  I got the powder 
from Harbor Freight.  I have several colors but black really to be the most 
appropriate.   The cost for a lifetime supply jar is only a few dollars.  

 

I use a razor blade to squeegee it into the etched areas and then bake it in my 
shop toaster-oven (my rex-kitchen toaster oven) for about five minutes.  I then 
clean up the surface with fine sandpaper and add as many coats as I like.  (As 
the shampoo bottle says, Rinse and repeat.) 

 

I will be interested to learn about variegated colors that simulate patina 
colors.  

 

Jack 

 

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Bill Gottesman
Sent: Sunday, September 20, 2015 1:11 PM
To: clar...@aol.com
Cc: Sundials List
Subject: Re:

 

Hello Ken,

 

I have tried some powder coating on aluminum with acceptable results.

 

1.  I do not have any powder coating facilities.  I bought small amounts of 
powder coat on the internet (I don't recall where, but could look it up), along 
with a small amount of a liquid solution that suspends the powder so I could 
paint in on with a brush.  I mostly used this to paint-fill engraved text, but 
also on some broader areas.  I then baked the part in my kitchen oven at the 
proper temperature (I think 325 degrees), and the results were very good.  Good 
adhesion, good appearance.  I can't yet speak to weatherability, but the 
product was advertised as UV (sunlight) stable.  

 

2. There is no question in my mind that electrostatically applied powder coat 
is superior to the brush-on method in terms of flatness of application and 
uniformity of color density.

 

3. Several powder coat suppliers sell colors that are variegated, meaning that 
the finished product is not of uniform color.  For example, I tried some copper 
and bronze patina colors that really looked good when baked, with the sort of 
small scale variations in color that you expect to see on patinated copper and 
bronze.  I can check my records for more details if you are interested.

 

-Bill

 

On Sat, Sep 19, 2015 at 6:34 PM, clarkkr--- via sundial  
wrote:

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-- Forwarded message --
From: clar...@aol.com
To: sundial@uni-koeln.de
Cc: 
Date: Sat, 19 Sep 2015 18:34:17 -0400
Subject: Looking for suggestings on surface treatment of my aluminum cross 
sundial "Time to Reflect"

Hi Everyone,

 

 I am looking for suggestions on different types of surface treatment that 
I could do on my aluminum cross sundial besides powder coating and enamel paint 
in the lettering.   I could anodize it but I am not sure it would hold up in 
the sun.  Would some kind of light acid etching work or some kind of staining 
on the aluminum?

 

 Thanks,

 

Ken Clark

Elizabethtown, PA

 

 

The following is my post from Facebook and link.

 

 

Time to Reflect sundial.

 

 This is a sundial that I been working on for over a year.  I designed this 
aluminum cross sundial on CORELDRAW which was saved as a DXF file and converted 
to SOLIDSWORK program and CNC by Max Machine of Elizabethtown, PA. 

 

  I am still looking at different options for the finish.  I have been 
thinking of powder coating it blue-green patina like the statue of Liberty.

 

 This is still a work in progress and is mounted over my well pipe for now. 
 I still need to fabricate the mounting bracket and will be bolted to probably 
an 18 inch diameter concrete base.  I need to find the right location or church 
that will accept this sundial.

 

 

Thanks,

Ken Clark

 

https://www.facebook.com/media/set/?set=a.10205271882252638.1073741827.1114522471
 

 &type=1&l=0a021f4dfa

 

 


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RE: Looking for suggestings on surface treatment of my aluminum cross sundial "Time to Reflect"

[Jack Aubert]

Tony Moss did a presentation somewhere a few years ago on anodizing
aluminum.   I have a vague memory of his doing something at one of the NASS
conferences, but it could have been the BSS bulletin or an email to this
list.  I think he used some kind of water soluble coloring that was absorbed
by open cells in the aluminum which were then closed up by the thin film of
oxidation.   I probably have this completely garbled but he did have a "how
to".  

 

Tony, can you provide a link to your anodized aluminum how-to?  

 

Jack

 

 

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Dave Bell
Sent: Saturday, September 19, 2015 7:08 PM
To: clar...@aol.com; sundial@uni-koeln.de
Subject: RE: Looking for suggestings on surface treatment of my aluminum
cross sundial "Time to Reflect"

 

I would suggest anodizing!

The best etch for aluminum is not acid, but alkali, and following that by
staining, essential *is* anodizing.

Here's one reference on various finishes:

http://www.saf.com/how-to-specify/how-to-decide-between-anodizing-painting-a
nd-powder-coating/

 

Note, "Anodizing is unaffected by sunlight"

 

Dave

 

  _  

From: clar...@aol.com [mailto:clar...@aol.com] 
Sent: Saturday, September 19, 2015 3:34 PM
To: sundial@uni-koeln.de
Subject: Looking for suggestings on surface treatment of my aluminum cross
sundial "Time to Reflect"

 

Hi Everyone,

 

 I am looking for suggestions on different types of surface treatment
that I could do on my aluminum cross sundial besides powder coating and
enamel paint in the lettering.   I could anodize it but I am not sure it
would hold up in the sun.  Would some kind of light acid etching work or
some kind of staining on the aluminum?

 

 Thanks,

 

Ken Clark

Elizabethtown, PA

 

 

The following is my post from Facebook and link.

 

 

Time to Reflect sundial.

 

 This is a sundial that I been working on for over a year.  I designed
this aluminum cross sundial on CORELDRAW which was saved as a DXF file and
converted to SOLIDSWORK program and CNC by Max Machine of Elizabethtown, PA.


 

  I am still looking at different options for the finish.  I have been
thinking of powder coating it blue-green patina like the statue of Liberty.

 

 This is still a work in progress and is mounted over my well pipe for
now.  I still need to fabricate the mounting bracket and will be bolted to
probably an 18 inch diameter concrete base.  I need to find the right
location or church that will accept this sundial.

 

 

Thanks,

Ken Clark

 

https://www.facebook.com/media/set/?set=a.10205271882252638.1073741827.11145
22471&type=1&l=0a021f4dfa


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RE: due east photos

[Jack Aubert]

Maybe it helps to bear in mind that while all triangles on a plane surfaces 
contain 180 degrees, this is not true on a sphere.  You cannot make a triangle 
on a plane surface that has two 90 degree angles because the sides will never 
meet.

 

On a sphere, however, a triangle can easily have two 90 degree angles.  If one 
side is congruent with the equator then the two sides will meet at the pole.  
The angle a the pole depends on the length of the equatorial side.  A triangle 
with three 90 degree angles will take up one eighth of the sphere’s surface.

 

East, west, north and south are spherical directions, not straight line on a 
plane surface. 

 

Jack Aubert

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Brent
Sent: Tuesday, September 15, 2015 9:47 PM
To: sundial
Subject: due east photos

 

I am having an off list discussion with Dave but I have a photo that you may 
find informative.

I resized them for the list so I hope you can see the latitude lines.

what you are seeing is my globe oriented on north south axis and correct angle 
for latitude.

I have a ruler close to my location with the zero on a latitude line

I am pointing the ruler due east, where the sun will rise on the equinox as it 
peaks over my horizon.

As we look straight down you see a deviation from the latitude line of about 1" 
at 4" on the ruler.

Just rough scale 4" = 4,000 miles so 1" equals 1,000 miles = 25% deviation.

My horizon is about 50 miles from here so when I look at the sunrise on the 
equinox my latitude is 
actually about 12.5 miles north of that point on the horizon.

So it's not an insignificant difference.

brent

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RE: Temporal Hours

[Jack Aubert]

HI Roger,

 

Thank you for sending the René Rohr reference.   I wish I had had it when I was 
writing my article for the compendium,  which on re-reading I find to be pretty 
incoherent.   René Rohr’s version is more or less what I should have written up 
to the  point where he explains the latitude mismatch.  I think René Rohr (and 
others) are wrong about the dial having been correctly made for somewhere else 
and then moved.   I have a copy of volume XXX of the archeological report on 
the excavation which covers the two sundials found at the site.  The report 
also includes the speculation, repeated by others, that it was designed for 
India or Syene, even though the report notes that the dial is made from 
limestone similar to other carved items, such as pillars, found at the site.
 

 

My own contribution to the Ai Khanum discussion is an admittedly speculative 
theory that the latitude mismatch could have resulted from a simple 
construction mistake.  I start with the assumption that the astronomer or 
mathematician who designed the dial specifications would not be the person who 
would do the physical construction including stone cutting.  I tried to imagine 
how one might go from a theoretical specification to actually marking lines out 
on a piece of stone at a time when most of the measuring tools and methods we 
might use did not exist or were not widely available.  I concluded that the 
specification of the angles would likely  have been stated in terms of ratios 
which would then have been realized by making right triangle templates to do 
the physical layout.  All the measurements needed for the  physical 
construction of this dial could have been specified by two triangles: one 
representing the earth’s obliquity and the other the local latitude.  My 
hypothesis is that the obliquity triangle was mistakenly used in place of the 
latitude triangle.  It is therefore not a random coincidence that the temporal 
lines which would be correct for a latitude of about 23.7 degrees is also the 
same as the earth’s obliquity at the time.  

 

But since my knowledge of paleo-mathematics is even weaker than my knowledge of 
stone-cutting techniques,  I would be interested in the opinions of those who 
know more about the period whether my “right triangle theory” is plausible.  

 

As Karlheinz has already pointed out, the Arachne of the Amphiareion is, of 
course, equatorial and not horizontal as I originally said.  

 

Jack  Aubert 

 

 

 

   

 

  

 

From: Roger Bailey [mailto:rtbai...@telus.net] 
Sent: Monday, August 03, 2015 8:13 PM
To: Jack Aubert; sundial@uni-koeln.de; Sasch Stephens
Subject: Re: Temporal Hours

 

Hi Jack,

 

While following a lead based on Sasch Stevens display at the conference, I came 
across an interesting article on the Al Khanum dial by Googling "Alexander the 
Great sundial". This search found this article: "A Unique Greek Sundial 
Recently Discovered in Central Asia" by Rene Rohr in 1980 in the JRASC. The 
article describes the work at Al Khanum by Paul Bernard. See 
http://adsabs.harvard.edu/full/1980JRASC..74..271R Their conclusion is the same 
as yours, the dial is a an equatorial with a polar gnomon but the lines show 
temporal hours rather that straightforward equal hours.

 

Regards, Roger

 

From: Jack Aubert <mailto:j...@chezaubert.net>  

Sent: Sunday, August 02, 2015 6:55 PM

To: schalda...@aol.com ; rtbai...@telus.net ; email9648...@gmail.com ; 
sundial@uni-koeln.de 

Subject: RE: Temporal Hours

 

I assume that you are referring to the Arachne of the Amphiareion.  I have a 
photocopy of your article on that dial, which was reconstructed from fragments, 
describing a (very old) horizontal dial with equal hours.  

 

Another atypical dial:  The Ai Khanum dial found in the ruins of Alexandria on 
the Oxus (in modern Afghanistan) that dates from approximately 145 BC is an 
example of a polar-oriented gnomon  with unequal hours.  This dial is 
interesting for several reasons, in particular the fact that while it 
“naturally” told equal hours using the line-shadow of the gnomon,  the 
constructor carefully incised lines to read unequal hours using the gnomon tip. 
  (It was done incorrectly for its latitude, but that’s another story.)

 

However, both these dials are quite exceptional.  My general impression from 
what I have been able to read is that equal hours were used by astronomers and 
astrologers.  While there is at least one example of a horizontal dial that 
uses equal hours and at least one example of a polar gnomon using temporal 
hours, people generally wanted their time in temporal hours so the vast 
majority of surviving dials prior to the Ibn al-Shatir dial used temporal 
hours.

 

Jack Aubert

 


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RE: Temporal Hours

[Jack Aubert]

I assume that you are referring to the Arachne of the Amphiareion.  I have a 
photocopy of your article on that dial, which was reconstructed from fragments, 
describing a (very old) horizontal dial with equal hours.  

 

Another atypical dial:  The Ai Khanum dial found in the ruins of Alexandria on 
the Oxus (in modern Afghanistan) that dates from approximately 145 BC is an 
example of a polar-oriented gnomon  with unequal hours.  This dial is 
interesting for several reasons, in particular the fact that while it 
“naturally” told equal hours using the line-shadow of the gnomon,  the 
constructor carefully incised lines to read unequal hours using the gnomon tip. 
  (It was done incorrectly for its latitude, but that’s another story.)

 

However, both these dials are quite exceptional.  My general impression from 
what I have been able to read is that equal hours were used by astronomers and 
astrologers.  While there is at least one example of a horizontal dial that 
uses equal hours and at least one example of a polar gnomon using temporal 
hours, people generally wanted their time in temporal hours so the vast 
majority of surviving dials prior to the Ibn al-Shatir dial used temporal 
hours.

 

Jack Aubert

 

From: schalda...@aol.com [mailto:schalda...@aol.com] 
Sent: Thursday, July 30, 2015 1:55 AM
To: rtbai...@telus.net; email9648...@gmail.com; sundial@uni-koeln.de
Subject: Re: Temporal Hours

 

 

 

 

Greek and Roman dials were not horizontal or vertical flat planar dials, but 
hemispheres, scafes or other projections of the sky onto a spherical or conical 
surface.  Planar dials came with the Islamic dials. 

Only a short note:This is not true. The first Greek dials were plane equatorial 
dials with equal hours. Karlheinz

The first planar dial with a polar gnomon was  by Ibn al-Shatir in Damascus in 
1371. This dial had  temporal hours, equal hours based on noon, sunrise and 
sunset, and Islamic prayer times, including reference lines to prayer times 
when the sun was well below the horizon. For me this dial is the epitome of 
sundials. It includes all the time systems in vogue at that time and for 
hundreds of years before and after. They all existed and were in common usage 
suited for different purposes. The question remains "Who is bringing the duck" 
for dinner. Time is important. Don't overcook it. 

 

Regards, Roger Bailey

 

 

 Michael <mailto:email9648...@gmail.com>  Ossipoff 

Sent: Wednesday, July 29, 2015 11:57 AM

To: Roger Bailey <mailto:rtbai...@telus.net>  ; sundial list 
<mailto:sundial@uni-koeln.de>  

Subject: Re: Temporal Hours

 

Roger, thanks for the answer. Ok, I shouldn't say that as a fact without having 
more information than I do. This is what I was implying or saying, without 
really having much support for it:

"In Europe and the fertile-crescent region, in ancient, classical and medieval 
times, before mechanical clocks (starting with Folliet-balance clocks) came 
into wide use, Equal Hours were of interest, for the most part, only to 
astronomers and astrologers. For ordinary civil timekeeping, for arranging 
meetings, keeping schedules or other civil/social purposes, Temporary Hours 
were preferred by pretty much everyone."

 

Were a fair percentage of people making their appointments and schedules by 
Equal Hours in the times and places named in the above paragraph?

I'm not being argumentative--I really don't know. 

--

Thanks for reminding me about Temporary Hours lines on Flat Dials being 
satisfactorily approximated by straight lines. I'd temporarily (no pun 
intended) forgotten that. It was a question that I'd asked, and received an 
answer to, when I first wrote to NASS.

Were Flat-Dials (for Temporary or Equal Hours) in use before mechanical clocks 
were getting popular?  What about _wide_ use? How early?

-

Can anyone explain why the early, inaccurate inertia-controlled Folliet-Balance 
clocks replaced the cheaper, more easily-made water-clocks? Were those 
earliest, most inaccurate mechanical clocks significantly, or any, more 
accurate than water-clocks?

Michael Ossipoff

 

 

 

 

On Tue, Jul 28, 2015 at 11:58 PM, Roger Bailey  wrote:

 Hi Michael  and all,

 

Temporal or Antique hours co-existed with equal hours from way back, thousands 
of years. It didn't take a technological device like a clock to cause a change. 
A more interesting point is the portrayal of temporal hours, 12 unequal hours 
in the day on a flat sundial. It is easy on Greek/Roman hemispheres but what 
about flat planar sundials. Is it sufficient to calculate the points for the 
solstices and draw a straight line between them? This works but is it right 
mathematically? To answer this question, Fred Sawyer gave an excellent 
presentation on Antique Hours at the NASS Conference in 2010 in Burlington. Was 
it re

RE: Sundial mounting question

[Jack Aubert]

Hi Kevin,

 

There are a couple of options for securing the dial to a base.   Since you are 
considering drilling some holes, it sounds like the birdbath base has a solid 
surface on top rather than an open cylinder .  

 

You could replace the bolt on the bottom center of the dial with a longer bold 
and nut so that you have a projection that could then be set into mortar in a 
depression made to receive it.  

 

But if you are not worried about theft or vandalism you can just adhere it to 
the pedestal with silicone caulk or with epoxy.This is what I would do.  If 
you use epoxy, which is probably stronger than silicone caulk, try to get a 
flexible epoxy.  

 

Jack Aubert 

 

 

 

 

From: KDConod [mailto:kdco...@yahoo.com] 
Sent: Thursday, June 25, 2015 12:09 PM
To: sundial@uni-koeln.de
Subject: Sundial mounting question

 

Hello Sundialers --

 

I used to lurk on this list years ago, I just rejoined and happy to see it is 
still around. Here's a practical question for you sundial experts

 

I have one of those reproduction "Mt Vernon" Virginia Metalworks brass 
sundials. I've had it in storage for years and recently acquired a concrete 
bird bath pedestal on clearance that I'd like to use to set the dial up on in 
the backyard.

The odd thing is that the dial has no mounting holes. There is a bolt on the 
bottom center of the dial that secures the gnomon but no other mounting holes 
are provided. (I guess they intended it to be gazed at adoringly as decoration 
and not actually used!)

 

I could go and punch two holes in it on either side of the gnomon but it seems 
a shame to ruin the nice brasswork.  So I'm wondering if you folks have any 
suggestions on securing/anchoring this to a concrete surface?

 

Kevin Conod
kdco...@yahoo.com


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RE: Painted dial

[Jack Aubert]

Hi Jackie,

 

I have done several dials like this cut from a large plastic board I
purchased several years ago.   The board is some kind of sign-board  ¾
thick, with high density foam core and smooth plastic on each side.  I
cannot locate either the name of this material or where I got it from, but
that wouldn’t help you much anyway,  since both are American and you are in
the UK.   Google for it.

 

My problems were mostly related to painting and stencils.  I used masking
tape for the hour lines and made stencils for the numbers.  Everything was
done spray paint.  There were two problems:  one was that I did several
layers of paint (background color, hour lines, motto) and the spray paint
types can be incompatible.  One layer caused all the lower layers to wrinkle
and I had to strip everything and start ofvr.  The second  problem were
caused by spray paint creeping under the masking tape and stencils.   Use
masking tape that claims it will make a sharp edge (e.g frog tape in the US)
and press it down well.  I made stencils by laying down overlapping 3”
masking tape strips onto waxed paper and put the printed text on top.  I cut
through everything with an exacto knife and after removing the paper pattern
from the top an waxed paper from the bottom, I was left with pretty good
stencils.  But I still ended up outlining both the hour lines and numerals
and motto with a fine black “paint” marker. 

 

Jack

 

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Jackie
Jones
Sent: Friday, May 08, 2015 12:47 PM
To: sundial@uni-koeln.de
Subject: Painted dial

 

Dear All,

 

I have been asked to do a painted dial for a south facing wall.  Due to lots
of reasons, I am going to paint it on board and then screw it onto the wall
when it is completed.  The wall is not suitable to paint directly onto and
it is some distance away from me.  

 

I thought of using exterior or marine grade plywood; has anyone who has had
any experience of this any tips or advice as to how to protect it so it will
last a good number of years?  Should I also paint the back and/or cover the
top edge of the wood?

 

Many thanks,

Jackie

 

Jackie Jones

50° 50’ 09” N0° 07’ 40” W

 


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RE: A "Digital" Sundial on Instructables

[Jack Aubert]

Yeah, I was wondering if there was any way to make it work purely with
cutouts.  I don't think so.  

I wonder if be made with optical fiber light guides.  I see that you can buy
10 millimeter fiber:

http://www.anchoroptics.com/catalog/product.cfm?id=446

But at some point, if you use enough modern technology, a sundial really
stops being a sundial.  

Jack Aubert


-Original Message-
From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Robert
Kellogg
Sent: Friday, April 24, 2015 12:01 PM
To: sundial@uni-koeln.de
Subject: A "Digital" Sundial on Instructables

Interesting digital dial.  I must admit I looked at this design about 20 
years ago.  The author has one 3D moveable drawing of the completed 
dial.  If you look closely on the underside of the gnomon, there are 
cut-outs of hour numbers that match the obverse side.

Therefore, this sundial works correctly only two days a year (I'm 
inferring that the numbers were aligned for the equinox).  Pity that 
such a beautiful digital dial is nearly useless.  Exactly the same 
problem with Voshart's digital cube (see 
http://gizmodo.com/this-digital-sundial-tracks-the-sun-through-a-laser-cut-1
545753402). 
This may force me back to the drawing board since I hold US Patent 
5,596,5533 Jan 21 1997 "Digital Sundial".  (See also Scharstein's US 
Patent 5,590,093 Dec 31. 1996 "Digital Sundial".  Dan's patent is 
earlier, but he had to reference my article in NASS' Compendium). A 
the modern digital world.

I understand that Apple's digital watches are being delivered to those 
few lucky souls today.
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RE: A question for the mathematically inclined

[Jack Aubert]

OK, I would also like to take a turn and ask a question to the mathematically 
inclined:

I have been trying to figure out how to plot the duration of daylight over the 
course of the year as a function of latitude.  (I would generate a curve for 
each latitude I am interested in.)  

I believe the result should be a sine curve which looks comparatively flat at 
the equator, growing increasingly steeper until the polar circle, where it 
would turn into a binary step curve and the six month day turns to six month 
night -- leaving aside physical effects like refraction.  I am particularly 
interested in the slope of the curve around the equinoxes at northern 
latitudes, when the transition from long summer days to short winter days is 
quite abrupt. 

Jack Aubert  

-Original Message-
From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of John Goodman
Sent: Sunday, February 01, 2015 12:37 PM
To: Sundial List
Subject: Re: A question for the mathematically inclined

Thanks to everyone who replied with suggestions, both on and off the list. 

When I asked my question, I assumed there was a trivial solution that could be 
simply explained. I realize now that the calculations are not straightforward. 

Roger Bailey has given me an approach that I believe will work for me. I’m now 
trying to understand how the math represents the spatial geometry of the 
problem. 

The variety of solutions I received are an indication of the broad experience 
and wisdom embodied in this group. I'm always grateful for that asset.


> On Jan 31, 2015, at 10:05 AM, John Goodman  wrote:
> 
> Dear dialists,
> 
> Does anyone know a formula for calculating the hour angle given the azimuth, 
> declination, and latitude? 
> 
> I’d like to know the time of day, throughout the year, when the sun will be 
> positioned at a particular angle. This will allow me to determine when 
> sunshine will stream squarely through a window on any (sunny) day.
> 
> I’ve seen several formulae for calculating azimuth. I suspect that one of 
> them could be rewritten to solve for the hour angle given the azimuth instead 
> of the finding the azimuth using the hour angle (plus the declination and 
> latitude). Unfortunately, I don’t have the math skills for this conversion.
> 
> Thanks for any suggestions.

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RE: Orologi Solari n. 6

[Jack Aubert]

Just learn Italian!  It takes a little effort but you can do it.

 It’s an excellent language and is useful for a number of things besides
gnomonics, including visiting Italy and listening to opera.  

 

Jack Aubert

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Reinhold
Kriegler
Sent: Tuesday, January 13, 2015 7:16 AM
To: David
Cc: gnomonicaitali...@yahoogroups.com; giancasale...@yahoo.it; Sundial list
Sundial list
Subject: Re: Orologi Solari n. 6

 

Dear David Brown!

The English language is probably not the NONPLUSULTRA within the Gnomonic
field!
Have you ever provided an Italian or German or French or Catalan or Spanish
version of a BSS magazine?
Have a look at these most manifold and beautiful 116 pages of OROLOGI SOLARI
n. 6 and you will be delighted!
You will find the download-link within the message of Gian Casalegno!

Enjoy!

And you also could by the way have a look at www.ta-dip.de , which you
certainly never have visited! :-)


Reinhold Kriegler


°


How do I get an English version, and how do I download it?
David Brown
Somerset, UK

On 12/01/2015 21:10, Reinhold Kriegler wrote:
Re: Orologi Solari n. 6 
Dear Gian Casalegno!

Thank you very much for this announcement!

Orologi Solari n. 6


... is a most splendid sundial magazine!

Lots of thanks to all the authors for this digitally free magazine!!!

Herzlichen Dank sagt
Reinhold Kriegler


°°


Dear all,
I'm glad to inform you that Orologi Solari n. 6 can now be downloaded from
<http://www.orologisolari.eu> www.orologisolari.eu.

This is the list of articles:
An ancient universal portable dial: the Pros-Pan-Klima - Paolo Albéri Auber
The new bifilar sundial at Aiello, with not straight wires - Riccardo
Anselmi
The sundial and the clock of the Cividale del Friuli's Cathedral - Miriam
Causero
Sundial design by means of the evaluation of two hour planes - Francesco
Caviglia
Sundials in the "Liberty" period - Enrico Del Favero
Lambert circles and Seasonal Markers in analemmatic sundials - Gianni
Ferrari
The parallel globe, directed and reflected gnomonic projections (part 4) -
Francesco Ferro Milone
The sundials of "Semplicemente Serra" - Pier Luigi Perino
A new method for reading a Moon dial - Pietro Poy
At sundials school - Ennia Visentin

As usual a bonus containing related files and programs is also available.

Greetings.
Gian Casalegno






* ** ***  * ** ***
Reinhold R. Kriegler
Lat. 51,83908° Nord, Long. 12,25512° Ost, GMT +1 (DST +2)
<http://www.ta-dip.de> www.ta-dip.de
 <http://www.ta-dip.de/dies-und-das/r-e-i-n-h-o-l-d.html>
http://www.ta-dip.de/dies-und-das/r-e-i-n-h-o-l-d.html


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RE: leap year

[Jack Aubert]

I'm sure there are more than two of us and my Latin is pretty minimal.  

The leap year date is a double-six (in French it is called "bissextile").
It is a second sixth date.  The "sixth" means six days before the March
calends (beginning of March).  Therefore there is a second February 24 so to
avoid the obvious confusion of having two dates with the same number, we
call the second one February 25 and increment the the rest of February
dates. s.  

... or something like that.  

Jack

  

-Original Message-
From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Richard
Mallett
Sent: Thursday, August 28, 2014 5:28 PM
To: Frank King; Jos Kint
Cc: sundial@uni-koeln.de
Subject: Re: leap year

On 28/08/2014 14:02, Frank King wrote:
> Dear Jos,
>
> You ask:
>
>> Has anyone an idea how to use a sundial for
>> calculating if the current year is a leap
>> year?
> Yes, been there, done that, got the T-shirt.
>
> The Noon Mark on the new London Stock Exchange
> in Paternoster Square more or less does what
> you want but once you understand it, you will
> probably decide to move on to a different
> project!
>
> The FIRST thing you should do is to get a
> feel for the leap year cycle and how it
> affects solar declination.
>
> Using some kind of solar calculator, such
> as:
>
>http://www.esrl.noaa.gov/gmd/grad/solcalc/
>
> you should do the following:
>
>Choose a date when the declination is
>changing quite rapidly.  We are near
>the autumnal equinox and I suggest you
>choose 22 September 2014.
>
>Then choose 12:00:00 as the time.  It
>really doesn't matter what time you
>choose, or what longitude, so long as
>you stick to the same time and place.
>
>If you are on the Greenwich Meridian
>then you will see that the declination
>is +0.23 degrees at 12h on 22 September
>this year.
>
>Then change the year to 2015, but don't
>change anything else.  You will see the
>declination is +0.33 degrees.
>
>Continue like this for about 36 years.
>Here are the first few values:
>
>  2014   +0.23
>  2015   +0.33
>  2016   +0.04
>  2017   +0.13
>  2018   +0.22
>  2019   +0.32
>  2020   +0.02
>  2021   +0.12
>  2022   +0.21
>  2023   +0.31
>  2024   +0.01
>
> OK, do you see the pattern?  Starting in a
> leap year, say 2016, the declination increases
> for the next three years and then jumps BACK to
> (but not quite to) where we started.  In 2020
> we are not quite where we were in 2016.
>
> If you have a large enough nodus height you
> can track tiny changes in declination.
>
> If you mark out a giant analemma you can
> divide it up into individual days, 366
> days including 29 February.
>
> If you concentrate on 22 September you can
> see that the declination is lowest in a
> leap year and then gets higher for the
> next three years.
>
> All this will work without ambiguity for
> about 36 years.  Then, the long-term
> drift [the Julian drift] results in you
> drifting into the previous day and the
> whole thing breaks down.
>
> I could get away with this on the new
> London Stock Exchange since the design
> life of the building is only 40 years
> and the plan will work most of the time.
>
> This scheme works, in theory, for almost
> any date but near the solstices the
> changes are too small to notice and you
> won't be able to detect them.  Worse, on
> the day of a solstice, the declination
> changes direction and it's a mess!
>
> Fortunately, 29 February is at a time of
> year when the declination is changing
> quite fast so you can mark that in quite
> nicely.
>
> For completeness, Leap Year Day is really
> 24 February but there are probably only
> two other people on this list who agree
> with that assertion!

And they both speak Latin :-)

>
> [I distinguish here between the extra
> DAY and the extra DATE in a leap year.]
>
> Very best wishes,
>
> Frank
>
> Frank King
> Cambridge, U.K.
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>


-- 
--
Richard Mallett
Eaton Bray, Dunstable
South Beds. UK

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RE: Michael Lee's Herbert Sun Clock in Model Engineer

[Jack Aubert]

I will try to find the etching article in my library.   

Our own Tony Moss is probably the foremost world expert in photo etching.
He has uploaded a two-part video on you tube showing the process of etching
a clock face with all the information one you would need to get started
photo etching brass dials with ferric chloride.  

I have been following in his footsteps and have succeeded in producing some
very nice dials using this method.  While I was perfecting my technique, I
developed a "how to" document with detailed information including a list of
materials and sources and an inventory of essential and optional tools.  If
anybody on this list wants to attempt photo-etching, I will be glad to share
my how-to document, which is meant to be used a supplement to Tony's video.


Jack Aubert
 

-Original Message-
From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of John
Pickard
Sent: Wednesday, August 13, 2014 7:24 PM
To: sundial@uni-koeln.de
Subject: Michael Lee's Herbert Sun Clock in Model Engineer

Good morning,

While browsing the current issues of Model Engineer at my local library I
found the following article:

Michael Lee (2014) A world sun clock. Model Engineer Vol 212, No. 4480, 18
April 2014, pp. 574-578.

VERY nice article about a SUPERB dial made to Alan Herbert's original
design, and how Michael made it. I especially liked the fine detail achieved
by etching the lettering and lines. Hand engraving has always scared me (way
too skilled for my shaky hands!), so Michael's etching is a real
inspiration.

***

In the same browsing session (the old fashioned kind of browsing: turning
the paper pages of a real analogue magazine!), I came across a very nice
detailed article on etching using photo-resists and ferric chloride. 

The instructions in the article may be of interest to list members:

Neil Wyatt 2014 A step-by-step guide to photo etching. Model Engineer, 7
March 2014, pp. 380-384.

Regards from a sunny but wintery cold Sydney,

John

Dr John Pickard


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RE: Sundials in Transylvania need your help!

[Jack Aubert]

Hi Dan,

 

Beautiful project. I’m also in for a minor contribution.  

 

I like paypal mainly because it spares me from having to remember or copy a 16 
digit credit card number.

 

Jack 

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Roger Bailey
Sent: Friday, August 15, 2014 12:36 PM
To: cerculdestele .; sundial@uni-koeln.de
Subject: Re: Sundials in Transylvania need your help!

 

Hello Dan,

 

What an excellent project! I have made a minor contribution to show support. 

 

Like most people these days, I am wary about internet security and privacy. 
Most of us are reluctant to provide personal information and credit card 
information. I did so using PayPal, a known and trusted method of transferring 
funds anonymously. 

 

Best wishes on the success of your project.

 

Roger Bailey  

 

From: cerculdestele   . 

Sent: Friday, August 15, 2014 2:55 AM

To: sundial@uni-koeln.de 

Subject: Sundials in Transylvania need your help!

 

Dear Group, 

 

Please have a look at my Indiegogo campaign.

It's about publishing a book dealing mainly with sundials in Transylvania. The 
manuscript is almost ready for printing. It will be the first photographic 
inventory/catalog of sundials in Romania (Eastern Europe).

 

The link is: http://igg.me/at/sundials

 

You can help by sharing the link and funding the project.

 

Many thanks!

 

Dan

  _  

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RE: Acrylic paint?

[Jack Aubert]

A google search for outdoor acrylic paint led me to a paint web site for some 
detailed information about suitability and preparation for painting outdoor 
murals:

 

http://www.goldenpaints.com/technicaldata/murals.php

 

Apparently, the answer is yes.  Acrylics are, according to the web site, 
color-fast and durable.  The washable emulsion paint should provide a good 
base.  

 

Are you painting this on-site by hand?  I have never been able to get 
satisfactory results – either straight lines or numbers or letters --  by hand 
painting.  I have had to resort to masking tape, stencils and spray paint.   
With spray paint you have to be careful to make sure that successive layers are 
compatible.  

 

Jack Aubert

 

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of cerculdestele .
Sent: Tuesday, August 12, 2014 10:16 AM
To: sundial@uni-koeln.de
Subject: Acrylic paint?

 

Hello!

 

I'm working on a vertical sundial at my job and I was wondering... is it a good 
idea to use regular artists' acrylic paint (the one you find in the 
supermarket) to draw the hour lines / dial furniture on exterior washable 
emulsion paint or do I have to use oil color?

 

Dan


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RE: The Bill Gottesman stance

[Jack Aubert]

Also note that the center of the body runs down more or less through the heels. 
 So the heals (or possibly the insteps) rather than  the toes should be lined 
on the date.  

 

Any more precision and we will need 5 minute lines!

 

Jack 

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Bill Gottesman
Sent: Saturday, May 10, 2014 4:13 PM
To: Robert Terwilliger
Cc: Sundials List
Subject: Re: The Bill Gottesman stance

 

I say we tack on as many names as possible.  Roger Bailey told me a few years 
ago he reported on this stance independently.  -Bill

 

On Sat, May 10, 2014 at 3:40 PM, Robert Terwilliger  wrote:

I have always been of the opinion that the optimal stance to assume as the 
gnomon of an analamatic sundial is to stand with one’s back to the sun with 
arms raised and palms together thus forming an arrow. What has been referred to 
as “The Gottesman Stance” would certainly be  a significant improvement.

 

I’m sure my friend Bill will agree with me that hereinafter in the literature 
the combination should be referred to as “The Terwilliger/Gottesman Stance”.

 

What say you?

 

ò¿ó¬

 ~

Bob

 

 

 

  

 

The Gottesman stance 


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RE: Sun tracks

[Jack Aubert]

Several of us have played with these pinhole long-exposure images following
a presentation by one of our NASS members at a conference two years ago.
The practitioners call this "solargraphy" although it should probably be
called heliography so as not to mix Latin and Greek. The photos are expected
to be somewhat funky with random defects and whatever false-color photoshop
or painterly effects you feel like introducing.   

While only tangentially related to sundials, this is a very accessible art
form, requiring mainly an empty can some photographic film and a way of
making a very fine pinhole.  Ideally, the dimension of the pinhole should be
a function of the focal length of the can's interior.  
 
Here are two that I did: The first one was taken from a rooftop terrace in
Brooklyn.  The second is a friend's house from across his pond. 

http://chezaubert.net/brooklyn2.jpg

http://chezaubert.net/froggy2.jpg

The sun tracks are really more of a secondary decoration than the point of
the photos.  

Jack Aubert  
 

-Original Message-
From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of rmallett
Sent: Monday, May 05, 2014 2:42 PM
To: Bill Gottesman; John Foad
Cc: Sundial list
Subject: Re: Sun tracks

On 05/05/2014 14:03, Bill Gottesman wrote:
> Here is what I think:
> The can is laying on its side with its axis oriented north-south.  A 
> pinhole is made on the west side of the can (assuming this location is 
> in the northern hemisphere, and that the zenith of the sun is toward 
> the south), pointing upward at about 45 degrees.  It captures the sun 
> before it has reached solar noon, then tracks it all the way to sunset 
> in the west.  The tracks of the morning sun at the top of the picture 
> appear to converge; this effect comes from that edge of the film being 
> so close to can's the pin-hole, where all light rays converge at their 
> origin.  (The film is wrapped around the inside of the can)
>
> -Bill

More conventional sunrise to sunset six month pinhole camera solargraphs 
periodically appear at
www.space-weather.com (and of course Google will find loads more)



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Eaton Bray, Dunstable
South Beds. UK

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RE: Algerian Prayer time dial

[Jack Aubert]

The second word along the vertical line is almost surely, Zawal, which is
the instant when the sun has passed mid-day, and the Zuhr may begin.I
cannot make out the first word. 

 

Jack

 

 

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Kevin
Karney
Sent: Friday, November 15, 2013 10:29 AM
To: sundial@uni-koeln.de List
Subject: Algerian Prayer time dial

 

Dear friends

Can anyone translate the arabic on this dial, which is in the Tiemcen museum
in Algiers?

 

My guess is .

the noon line reads Dhuhr

the next line is the start of Asr (length of shadow = height + length of
noon shadow)

the next is the start of the 'time of necessity'  for Asr (when the sun
turns orange before sunset)

the rubric at the bottom gives the height of the nodus

 

Thanks

Kevin


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RE: Algerian Prayer time dial

[Jack Aubert]

 

 

This query prompted me to consult Gianni Ferrari's excellent book on ancient
Islamic Sundials.  I expect that Gianni will be able to clear it all up once
he is on line and able to chime in, but meanwhile I can't resist guessing:


 

The script is Kufic, or kufic-ish, which is hard to read.  

 

The last line on the right clearly says "Asr":  The letters are 'ayn-sad-ra


 

The middle line looks like it starts with dh- and ends with ra  I think it
probably says Dhur or Zuhr although I cannot make out the middle which
should be a ha.  Zuhr starts at mid-day but continues until the beginning of
Asr so this line would be the end of Zuhr making the last line the end of
Asr, or second Asr. 

 

The script along the vertical line is completely beyond me but I am pretty
sure there is no Dhur in there. 

 

Jack Aubert

 

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Kevin
Karney
Sent: Friday, November 15, 2013 10:29 AM
To: sundial@uni-koeln.de List
Subject: Algerian Prayer time dial

 

Dear friends

Can anyone translate the arabic on this dial, which is in the Tiemcen museum
in Algiers?

 

My guess is .

the noon line reads Dhuhr

the next line is the start of Asr (length of shadow = height + length of
noon shadow)

the next is the start of the 'time of necessity'  for Asr (when the sun
turns orange before sunset)

the rubric at the bottom gives the height of the nodus

 

Thanks

Kevin


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RE: Re: Re: Shape of Greek and Roman sundials

[Jack Aubert]

The “Ai Khanum” dial  that Rohr studied was on tour a few years ago along with 
various artifacts from Afghanistan and made a stop in Washington DC, the area 
where I live.

 

Perhaps the most interesting thing about the dial  is not so much that it is 
cylindrical, but that it uses a polar orientation while being designed to tell 
unequal, or  temporal. hour lines.  I believe the polar orientation is 
virtually unique for ancient dials.  Normally a polar orientation would 
generate equal hours, but the Ai Khanum sundial is inscribed with temporal 
hours, presumably because temporal hours were what people actually used and 
wanted.  The other interesting thing about the dial is that it appears to be 
designed and built and oriented for the location where it was found, Ai Khanum 
in Afghanistan, but the inscribed temporal hour lines were calculated for a 
different latitude of approximately 23 degrees.  This poses something of a 
mystery. 

 

I did a study of this dial, which was published in the NASS compendium, and is 
also at http://chezaubert.net/AiKhanum/AiKhanum.pdf.  My own study drew heavily 
on Rohr’s paper, along with measurements taken from the original archeological 
report.  I came to the admittedly very speculative conclusion that the 23 
degree hour line layout was the result of a construction error stemming from 
confusing the two triangles that could have been used to specify all the angles 
needed to construct the dial.  This led to further speculation that, absent 
standardized units of measure, Hellenic sundial calculation and construction 
techniques were probably specified by using triangles and ratios.   

 

Jack Aubert

 

 

 

   

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of 
nicolasever...@libero.it
Sent: Wednesday, October 23, 2013 3:48 PM
To: sundial@uni-koeln.de
Subject: R: Re: Re: Shape of Greek and Roman sundials

 

Dear Sasson, 

I think the accuracy to plot the hour lines on a cylindrical surface is more 
easy that a conical surface, but I not think that in the Roman era there was no 
need of the minutes of precision! In any case, sorry for your sentence " not a 
single cylindrical dial has been found.", because Sharon Gibbs described 6 or 7 
cylindrical roman sundials and René J-R- Rohn written a famous paper about this 
topic in the 1980. His article you can read here:

 http://adsabs.harvard.edu/full/1980JRASC..74..271R

 

The best wishes, Nicola

 

 

Messaggio originale
Da: saskauf...@gmail.com
Data: 23/10/2013 18.57
A: "nicolasever...@libero.it", 
Ogg: Re: Re: Shape of Greek and Roman sundials

Thanks, Nicola.

Obviously, one can achieve accuracy if so desired on any surface, yet at least 
to my reckoning it would be more difficult. 

Am I mistaken about my assumption that with a cylindrical surface it's far 
easier to plot the lines and achieve accuracy? Because if I'm correct, I would 
have expected at least some cylindrical dials to surface, yet to the best of my 
knowledge (and from your comprehensive knowledge you'd surely be able to affirm 
or contradict this statement), not a single cylindrical dial has been found. I 
somehow dislike the notion that I'm smarter than all of the dial makers of the 
ancient world, especially, since some of them did manage to plot accurate lines 
on spheres and cones, proving that they were in fact quite smart. 

 

On Tue, Oct 22, 2013 at 11:47 PM, nicolasever...@libero.it 
 wrote:



Dear Sasson, 

 

I think the precisione in the roman sundials depend from the ability of the 
marble workers.

The greco-roman sundial in the attached images, from the Vatican Museum,   
probably shows that it is able to point out a precision approximately of  the 
minute. 

Nicola

 

 

Messaggio originale
Da: saskauf...@gmail.com
Data: 22/10/2013 21.52
A: "Schechner, Sara", 
Ogg: Re: Shape of Greek and Roman sundials

 

Thanks for your reply, Sara.

Although the dial in my previous message doesn't seem cylindrical, I can assure 
to you that it is. See the attached side-view of the dial taken from the 
TinkerCad file.

If I understand correctly, you confirm my suspicion that the concave dials were 
not accurate to the minute, and furthermore, you claim they weren't meant to 
be. Some of the dials however show quite a high level of craftsmanship, and I 
therefore find it a bit surprising that those who invested painstaking efforts 
into their dials didn't strive towards accuracy, unless like you say, from 
their perspective it was more important to have the dials shaped like the 
heavens.

Sasson

 

On Tue, Oct 22, 2013 at 7:02 PM, Schechner, Sara  
wrote:



Dear Sasson,

 

Your sundial looks pretty, but it does not seem cylindrical to me in the photo. 
   

 

As for your questions concerning the preference of the Greeks and Romans to 
concave spherical sundials, there are several answers:

 

1. The bowl mirrored th

RE: News article

[Jack Aubert]

.and an excellent article, too.  

 

The journalist understood what John said and wrote clearly.  My experience
with news reports has been that most of the details get completely garbled.
This one was not garbled.  Kudos to Alan Petrillo, the journalist, and of
course to John Carmichael.   

 

Jack Aubert

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Fred Sawyer
Sent: Friday, September 20, 2013 12:19 PM
To: Sundial List
Cc: Bob Kellogg
Subject: News article

 

Congratulations to John Carmichael on being featured in an article in Inside
Tucson Business.

http://www.insidetucsonbusiness.com/news/profiles/ancient-time-form-in-stone
-is-carmichael-s-specialty/article_43fab1b6-216c-11e3-88ba-001a4bcf887a.html
?mode=jqm

Fred Sawyer 
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RE: Is there something wrong with this Cassiopeia video?

[Jack Aubert]

Yes I would say that there is something wrong with the video.

 

The figure-eight shaped analemma is generally attributed to Grandjean de
Fouchy, a French mathematician who devised it around 1740 as a way to
regulate mechanical clocks by reference to the sun.The device was called
the "mean time meridian" and was laid out on an interior the floor using
markers on two sides of a straight north-south noon meridian line.  A spot
of Sunlight was projected onto the floor thorough a ring gnomon outside the
building through a window.   The sun's image would cross the "mean time
meridian" line at exactly noon as measured by a perfectly accurate ideal
clock and could therefore be used to regulate an actual clock.  

 

The mean time meridian or analemma, therefore, was more of an invention than
a discovery and is only meaningful because of the juxtaposition of mean time
clocks and solar time.  When a clock is connected to a camera, the same
figure emerges in the sky if a photo is taken at the same time on successive
days.  

 

Since the analemma (mean time meridian) was originally developed with
reference to noon meridian line, it does have a logical connection to noon,
but the photos of the sun that trace out the figure in the sky are generally
not taken at noon. 

   

The slope of the figure is a function of latitude.  Its position (higher or
lower) above the horizon is a function of the time of day that the photos
are taken.  Morning and afternoons provide more interesting background
scenery. 

 

The values of the true sun's deviation from a mean sun were actually
explained and calculated by Ptolemy in the Almagest!  However the graphic
representation of these values that we call the analemma would probably
never have arisen without the intervention of a mechanical clock. 

 

The upper and lower limbs of the analemma do correspond to the two
solstices, but the crossover point when clock time deviates from solar time
is not related to the equinoxes.  This appears to have been a plausible (but
wrong) guess by somebody.  

 

Jack Aubert

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of ruben
nohuitol
Sent: Monday, July 29, 2013 6:12 PM
To: sundial@uni-koeln.de
Subject: Is there something wrong with this Cassiopeia video?

 

Hi, I watched this video,
<http://www.youtube.com/watch?v=IhqzW97_47w&feature=share&list=PLgLV7Kpk8Y6G
DdceXQCmgDLgbYSH7TeSt>
http://www.youtube.com/watch?v=IhqzW97_47w&feature=share&list=PLgLV7Kpk8Y6GD
dceXQCmgDLgbYSH7TeSt , of the Cassiopeia Project, in the 2th minute says the
equinox is marked for the cross point of the analemma, which I found not
match with my analemma but not with others, as show in pictures anexed.

 

Also found they say the marks are at noon, if noon means solar midday it is
not true, because the marks made a meridian line, not an analemma, and if
noon means 12:00 there´s no point to mention it, because you can make the
mark at any hour, just taking care is the same hour.

 

The video shows an left inclinated analemma, showing is at morning, not at
noon in any case. 

 

The image of the analemma is very close to the earth in case of a real photo
secuence, note the winter solstice point is very close of the earth, except
the case of the picture is taken very very close of the north pole, I
assume.

 

By the way, please tell me if there´s a method which shows graphicly the
equinoxes on a analemma, because I heard they need to make an analemma for
exactly know when the equinox are.

 

Thank´s 

 


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RE: Sundials in schools

[Jack Aubert]

Just don't quit your day job quite yet.

 

Jack Aubert

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Donald
Christensen
Sent: Thursday, July 25, 2013 7:08 PM
To: sundial@uni-koeln.de
Subject: Sundials in schools

 

My sundials haven't sold as well as I hoped. In fact they haven't sold at
all. Any advice you can give would be greatly appreciated.

 

Some of the things I know

 

X and Y coordinates are also given with my sundial. However, I promoted
triangulation too much and people are unaware that I give measurements in
the Cartesian coordinate system as well. This is confusing. I may drop
triangulation all together. I'm slow to take this out because I cannot edit
my movie. My movie software no longer works. Perhaps I will drop the movie
altogether.

 

I promoted the learning outcomes aspect of my sundial. Perhaps I shouldn't.
Schools can quickly say, "We don't have time for any other activities" and
therefore they look no further. It doesn't even occur to them that the
sundial enhances any playground. It does not have to become a learning
activity or be constructed by the children. What is your opinion?

 

I don't have photos of children on my website. I don't have any because I
haven't sold any. I tried to give some sundials away but can't. I'm a
terrible salesman and sound more like a telemarketer.


Cheers   
Donald Christensen
0423 102 090   
www.sundialsforlearning.com <http://www.sundialsforlearning.com/>

 
<http://content.screencast.com/users/dchristensen777/folders/Default/media/d
641cee8-137c-456d-afc1-334e75526254/logo%20GIRL_SHADOW.gif> 





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RE: sundial for a blind person

[Jack Aubert]

You are right, Mike:  Here is a photo of the dial  from the report on our 
Vancouver conference.  

I don’t recall any write-up or presentation, though.   

 

 



Chuck Nafziger’s light concentration sundial, complete with

Braille markings.

 

 

 

 

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of 
jmikes...@ntlworld.com
Sent: Wednesday, July 03, 2013 1:37 PM
To: Brad Dillon; Sundial List
Subject: Re: sundial for a blind person

 

I have a vague memory of one being shown at the NASS Conference in Vancouver 
back in 2006.

I think it was called a “Light concentrating sundial” and was made by Chuck 
Nafziger.

Or am I imagining it?

 

Mike Shaw
53º 22' North 03º 02' West
www.wiz.to/sundials

 

 


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RE: sundial spotting

[Jack Aubert]

As we learned on a BSS tour of the Perche region in northwestern France two
years ago there are many sundials in that area that use the crescent moon as
a decorative element.  Here are a few more of them:

 

http://michel.lalos.free.fr/cadrans_solaires/autres_depts/orne/perche_ornais
/cs_de_mortagne.html

 

A booklet on local sundials published by the Perche tourism office asserts
that the role of these decorative elements, including a few other shapes, is
to stop the hour lines so that they don't converge to a point and lose
definition, either by having the stone break up or the painted lines run
together.   The crescent may just be something that became locally
fashionable in that region of France when the dials were being constructed.
I think that is probably a more plausible explanation than looking too
deeply for religious symbolism.   

 

Jack Aubert

 

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Steve
Lelievre
Sent: Sunday, June 09, 2013 10:53 AM
To: sundial@uni-koeln.de
Subject: Re: sundial spotting

 

Hi all,

What, if any, is the significance of the recumbant crescent in this dial?
Wikipedia describes crescents in art and symbolism, but its description
relates mostly to the crescent as a symbol of Islam and in Christianity
(Roman Catholic) as a symbol for Mary.

Is there any other or more specific meaning when used to furnish a dial?
Specifically, a fully recumbant crescent as shown in this dial?

Steve



On 09/06/2013 9:11 AM, Fred Sawyer wrote:

Karin,

See a photo of the dial at

http://michel.lalos.free.fr/cadrans_solaires/autres_depts/orne/pays_d_alenco
n/cs_pays_d_alencon.html


Fred Sawyer


On Sunday, June 9, 2013, Karin ten Kleij-Meij  wrote:
>
> Dear sundial people,
> Does the cadran solaire on this piece of art look familiar to you? :-)
> http://en.artscad.com/A.nsf/OPRA/SRVV-6D4TP2
> Best regards and wishing you a sunny day,
> Karin. 




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RE: Re quicklime

[Jack Aubert]

This is all fascinating stuff and I will either impress or bore people  with
my bogus erudition on the subject. 

 

But Is there an easy way to distinguish lime mortar from Portland cement
mortar, like with one's thumbnail?  In America, the oldest brick buildings
on the East Coast are from the mid 18th century but they would generally
have been re-pointed with Portland cement.  Last weekend I was checking
mortar joints in Alexandria, Virginia, where the oldest buildings date from
that period.  They all seemed to have the same sandy consistency.  I
jokingly told a homeowners that I was the "mortar inspector".  He replied
"Finally!  We've been waiting forever!"  

 

Jack

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Kevin
Karney
Sent: Monday, May 06, 2013 2:39 PM
To: Sundial
Subject: Re: Re quicklime

 

A further point about lime mortar. It sets quite hard within a few weeks,
but continues to get harder & harder at an exponentially slower rate until
the carbon dioxide (as carbonic acid) in the atmosphere eventually converts
it back to its original calcium carbonate. So Roman mortar is very very hard
and totally inflexible.. Yes!,  it can take thousands of years to re-convert
- this is one of the reasons why ancient buildings (as Roman aqueducts) last
so long. The conversion is quicker in cold climates since frost makes micro
cracks which allows the carbonic acid to percolate into the mortar.

 

CaCO3 (limestone) ---heat---> CaO (quicklime)+ CO2

CaO (quicklime)+ H20 ---> Ca(OH)2 (slaked lime)

CO2 + H2O --- in the atmosphere ---> H2CO3 (carbonic acid - very weak)

Ca(OH)2 (slaked lime) + H2CO3 + O2  time ---> CaCO3 (limestone) + 2H20

My chemistry is very rusty - so I hope the formulae are right

 

All the best 

Kevin

 

On 6 May 2013, at 15:32, Frank Evans  wrote:





Greetings, fellow dialists,
I'm now clearer on the subject of lime production. After firing It seems the
quicklime was taken from the kiln in lumps, separated from the ash and moved
to a pit in the nearby slaking shed (cheaper than iron pots). The pit was
lined to hold water and the quicklime was (cautiously!) added. It was in
timer bailed out and sieved (large lumps might not be completely slaked and
could "blister" later as mortar, with damaging consequences. The resulting
slaked lime could now be safely transported. Each firing produced several
tons of lime and this was sometimes left to mature for many weeks.

Thanks to all who replied. I hope to talk further on the subject with the
stonemason when he returns to Tynemouth in the summer to paint the dial. I
note he was careful to chose the correct colour of sand to mix with his lime
putty for the repairs.
Frank 55N 1W
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RE: new Italian magazine on line

[Jack Aubert]

I would like to subscribe.  Will the reborn review  only be available on-line 
for foreign subscribers?  If so, we would need an e-mail notification for new 
issues.   

 

Jack Aubert

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of 
sun.di...@libero.it
Sent: Sunday, April 21, 2013 5:07 AM
To: Sundial list Sundial list
Subject: new Italian magazine on line

 

Dear friends,

I guess most of you have seen or simply heard in the past about the Italian 
magazine Gnomonica Italiana.

It has been the main reference for all the Italian dialists for several years.

Unfortunately when Mario Arnaldi left the management it was impossible to find 
someone who could take his place.

We so had a one year gap waiting for a solution.

 

Now I am happy to let you know that a new managing committee has taken on the 
responsibility of a new magazine.

 

Its name is "Orologi Solari" (Sundials).

 

It introduces several changes with respect to the past.

The new magazine is free. The first issue is ready and it can be downloaded 
from the site www.orologisolari.eu <http://www.orologisolari.eu/> .

A digital bonus is associated with this issue and it is available for 
downloading too.

Every article is summerized by a short abstract in Italian as well as in 
English and French.

Papers from foreign dialists are welcomed: f.i. issue n. 1 contains a French 
article both in the original language and in Italian.

The publication frequency will be four-monthly.

 

The managing commettee invites you all to have a look at "Orologi Solari" and 
hopes you will enjoy this result of the Italian gnomonic community.

 

Greetings.

Gian Casalegno


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RE: Today's Google Banner - More

[Jack Aubert]

But why his 306th birthday?  What is the significance of 306?  Am I missing
something obvious?

Jack


-Original Message-
From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Frank King
Sent: Monday, April 15, 2013 4:30 AM
To: sundial@uni-koeln.de
Subject: Today's Google Banner - More

I should, of course, have added:

   Happy Birthday to Leonhard Euler

306 years old today and still going
strong!

It is a happy coincidence that he
should have been born on the day
that the Equation of Time changes
sign.

Frank King
Cambridge, UK

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RE: Art in dialling

[Jack Aubert]

The  city-direction labels are a nice touch:  an old tradition that seems to
have fallen into disuse.  I hope you can tell us  how the concrete (?) bowl
was constructed.  

 

Jack

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Bill
Gottesman
Sent: Sunday, April 07, 2013 3:40 PM
To: f...@solariameridiane.it
Cc: Sundial sundiallist
Subject: Re: Art in dialling

 

Hello Fabio,

 

Marvelous public sundial!  How did you construct the concrete bowl, and mark
the lines so straight?  I imagine it has a drain for water.

 

-Bill

 

On Sun, Apr 7, 2013 at 12:14 PM, f...@solariameridiane.it
 wrote:

Hi all

this is my work in 2006, created for the city of Borgo San Dalmazzo (CN)
Italy. The development of the project saw the collaboration of Fabio Savian.

I do not know if it falls between the sundials you are looking for.

www.sundialatlas.eu/atlas.php?so=IT8328

 

Fabio Garnero

 

Il giorno 06/apr/13, alle ore 21:12, Mario Arnaldi ha scritto:





Hi all,

 

I am working to an article about the Art in dialling and I would like to
collect high resolution images of sundial made by artists or also artistic
sundials. I know that not only Italy is the land of art so I would ask if
there are some dial made by an artist ouside the Alps, or some artistic
sundial to include as picture in my article. For example I know the famous
Dalì sundial, the sundials made by Henry Moore, the dial made by Cocteau.
There is some other dial of that kind?

 

Mario Arnaldi

 

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RE: John Carmichael's Railway

[Jack Aubert]

Hey John, post more videos!  
This stuff is unbelievable.  
True that it is off topic, but I think the sundial list can indulge you (and
the rest of us) a little bit more.

Jack

-Original Message-
From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of John
Carmichael
Sent: Monday, January 07, 2013 4:26 PM
To: 'Mac Oglesby'; sundial@uni-koeln.de
Subject: RE: John Carmichael's Railway

Thanks to all who wrote back.  Who knew railroads would be popular with
sundial guys.  Nevertheless, this will be my last email to the Sundial list
about this railroad since it IS a sundial List.  Mac, you got me thinking
that I might be able to avoid YOU TUBE and use Flickr instead to post a
video.  Turns out it was easy!  Here is a quick video of loco on trestle:
http://www.flickr.com/photos/jlcarmichael/8357925747/in/set-7215763243055283
7/


John  C 

-Original Message-
From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Mac Oglesby
Sent: Saturday, January 05, 2013 6:56 AM
To: sundial@uni-koeln.de
Subject: John Carmichael's Railway


Hi John,

Your railway is absolutely marvelous! And I'm very happy to learn you are
well and active.

Inevitably, you or a friend will make videos of your project in action.
Please don't neglect to notify the list when and where the videos may be
viewed.

Very best wishes,

Mac

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RE: Sundials in playgrounds - at last, "the tide is turning" !

[Jack Aubert]

It is interesting to note how the Health and Safety Executive was able to
take a thought that could be succinctly expressed in two sentences and turn
it into fifteen numbered paragraphs pages with two footnotes by spinning out
variations and permutations on a simple theme.  If it were set to music the
composer would have to be Philip Glass

Jack Aubert


-Original Message-
From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Martina
Addiscott
Sent: Friday, September 14, 2012 6:37 AM
To: sundial@uni-koeln.de
Subject: Sundials in playgrounds - at last, "the tide is turning" !


Following-on from previous correspondence, it actually seems that the UK
"Health and Safety Executive" have realised just how ridiculous it is for
schools to be 'banning' any outdoor activities - simply because there was a
small element of risk involved, which might ultimately result in some legal
action.

They have now issued a statement (see the attached PDF file), in an attempt
to clarify this unfortunate situation - which was causing Analemmatic
playground layouts to be discouraged, both here in the UK and in other
countries such as Australia.

This might be of use to list-member Donald Christensen - whom I know is
active in this area, within the Australian system.


So it looks like "the tide might be turning", back to a more 'sensible'
approach to evaluating levels of risk to children, and as well as the
attached file there is further information at
http://charityemail.org.uk/LJV-YM4F-39UDPL-DE93G-0/c.aspx


Sincerely,

Martina Addiscott.



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RE: IMAGES APLENTY

[Jack Aubert]

Not in the NASS registry!  Does anybody live in South Carolina?

 

From: sundial [mailto:sundial-boun...@uni-koeln.de] On Behalf Of Fred Sawyer
Sent: Tuesday, August 28, 2012 3:23 PM
To: Tony Moss
Cc: Sundial List
Subject: Re: IMAGES APLENTY

 

Tony,

There is a large version of that Manship gnomon (one of my favorites) at
Brookgreen Gardens in South Carolina.  To see images of it, go to:

http://commons.wikimedia.org/wiki/File:Sundial_at_Brookgreen_Gardens.jpg

http://www.youtube.com/watch?v=U3XDJ4MH86s

http://swordsandswimmers.blogspot.com/2010/07/brookgreen-gardens.html

Fred







On Tue, Aug 28, 2012 at 1:39 PM, Tony Moss 
wrote:

The following answered one ofmy question viz. 'What was the full size dial
made of?

http://www.1939nyworldsfair.com/worlds_fair/wf_tour/statues/fates_of_man.htm
-  

...which turns out to be plaster and explains the white colour.
Somehow I doubt if the huge full-size version could have survived anywhere
but the small bronze? model on a marble? base must be preserved somewhere.

Any ideas?

Tony M.

P.S.  Many of the images my name spawns in Google Images seem to come from
websites and PowerPoint presentations. 'Big Brother' seems to be watching.

 

 

-Original Message-
From: David Bell 
To: 'Roger Bailey' ; 'Tony Moss'
; 'Frank King' 
CC: sundial@uni-koeln.de
Sent: Tue, 28 Aug 2012 6:43
Subject: RE: IMAGES APLENTY 

That might not be *the* reason, but I am certain that Google search on your
computer does "know you". Pros and cons...
 
-Original Message-
From: sundial [mailto:sundial-boun...@uni-koeln.de
 ] On Behalf Of Roger
Bailey
Sent: Monday, August 27, 2012 8:52 PM
To: Tony Moss; Frank King
Cc: sundial@uni-koeln.de
Subject: Re: IMAGES APLENTY 
 
Yes, Google Images offers many hits, mostly irrelevant. Frank King BSS 
Cambridge brings up only one image. Ditto Frank King sundials. Roger Bailey 
sundials brings up 10 legitimate hits on my computer, the first ten of many 
irrelevant hits. Is this because Google searching on my computer knows me?
 
Regards, Roger Bailey
 
--
From: "Frank King" 
Sent: Monday, August 27, 2012 10:02 AM
To: "Tony Moss" 
Cc: 
Subject: Re: IMAGES APLENTY
 
> Dear Tony,
> 
> Google Images indeed represents a splendid
> resource and you can find lots of good pics
> of sundials and, if you wish, pictures of
> noted celebrities too.
> 
> Try entering "Tony Moss" and you will see
> that you have more impersonators than Elvis!
> Still, the real thing is there around image
> Number 20 and again at around Number 70.
> 
> Just keep going and you will come to the
> sundials too!  You will find pieces about
> you and your dials in Polish and French,
> but you know all that already!  I really
> like the WizardWand sun-substitute.
> 
> Gee, what it is to have such CyberFame!
> 
> All the best
> 
> Frank
> 
> ---
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> 
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Re: Tony Moss Email

[Jack Aubert]

It looks like the DNS domain lindisun.demon.co.uk has lapsed.


> Does Tony Moss have a new email address? The t...@lindisun.demon.co.uk
> address is now reported as Unrouteable.
>
> Larry McDavid
> Sundial Registrar
> North American Sundial Society
>
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RE: Solar Eclipse Sundial

[Jack Aubert]

We had one like that when I was living in Morocco.  We had driven from Rabat
to Casablanca to see it, and were sitting on a terrace drinking beer when it
happened.
  
I call them nebular eclipses.  

Jack

-Original Message-
From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of Roger Bailey
Sent: Sunday, May 20, 2012 11:36 PM
To: Sundial List
Subject: Re: Solar Eclipse Sundial

Hi Bill and all,

The weather forecast for the eclipse was correct. The weather was rotten: 
the eclipse here was obscured by clouds. The loss of light from the eclipse
was not any different from a darker patch of clouds. However, I was able to
observe the eclipse. At the time of the eclipse maximum, the clouds did
clear enough to see that the eclipse was in progress in progress. See
attached photo. No optical aids like pin hole cameras, binocular projections
etc were required. The sun was barely visible to the naked eye  through the
clouds. There were no opportunities to explore an eclipse sundial like the
one you proposed for San Mateo (San Francisco). I hope others had clearer
skies.

The picture was taken at 6:17 pm PDST. The times listed below are standard
time, an hour earlier so the picture shows the eclipse maximum in Victoria
BC.

Regards, Roger bailey

--
From: "Roger Bailey" 
Sent: Thursday, May 17, 2012 9:13 PM
To: "Sundial List" 
Subject: Fw: Solar Eclipse Sundial

> Hello again,
>
> Thanks Bill. Your note alerted me to check further and to prepare for 
> observations. I did some checking based on your note and now see this 
> is something to look forward to. The eclipse will be fairly 
> significant even if I am north of the center line. I will set up a 
> system to observe and photograph the event but cloud and rain is 
> forecast for Sunday after a week of summer sunshine.
>
>Eclipse Max. Eclipse Sun Sun 
> Eclip. Eclip.
> Location Begins Eclipse Ends Alt  Azm 
> Mag. Obs.
> h m  h m  h m ° °
> Victoria, BC16:00   17:16   18::25 24  274 0.819 
> 0.751
> San Mateo, CA  16:15   17:32   18:39  19  282  0.897 
> 0.842
>
> http://eclipse.gsfc.nasa.gov/OH/OHtables/OH2012-Tab02.pdf
>
> See you in Asheville.  Regards,
> Roger Bailey
>
>> --
>> From: "Bill Gottesman" 
>> Sent: Thursday, May 17, 2012 10:53 AM
>> To: "Sundial Mailing List" 
>> Subject: Solar Eclipse Sundial
>>
>>> Hello Sundialists,
>>>
>>> Here is a link to a new type of paper sundial made specifically for 
>>> the partial solar eclipse viewed from San Mateo, California this Sunday.
>>> You need a simple pin-hole projector (a card with a small hole in 
>>> it) to use it.
>>>
>>> http://tinyurl.com/86gtkcr  (file is a .pdf that can be printed for 
>>> use)
>>>
>>> If anyone will be in the area at that time, I would love to hear if 
>>> it works, and see a photo of it in use if possible.  The math was 
>>> more challenging than I expected.
>>>
>>> I plan to talk a little bit about this project at the NASS meeting 
>>> this summer in Asheville, NC.
>>>
>>> -Bill
>>> ---
>>> https://lists.uni-koeln.de/mailman/listinfo/sundial
>>>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
> 


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RE: Equinox Derivative: dx/dt Sin x = Cos x

[Jack Aubert]

An attempt to understand this phenomenon was what sparked my interest in
sundials in the first place.   I lived for two years in Helsinki, a of the
“land of the midnight sun” , and while the long winter nights and long
summer days were certainly striking to somebody arriving from a more
southern latitude,  the strangest thing for me was the rapid change in the
day’s length around the equinoxes.   Summer seemed to explode from nowhere
out of winter: suddenly everything was green and vines raced up the
building.   In Autumn, summer drained away suddenly like water rushing from
a basin when the plug was pulled.I had always just assumed –without
thinking about it --  that the length of the day changed regularly
throughout the year.   Back at 39 degrees North, where I now live, the
difference in the rate of change is perceptible, but easy not to notice if
you don’t pay attention to these things.   What is really interesting about
this phenomenon is how much the rate of change is affected by latitude.
Above the arctic circle, I guess the curve becomes almost discontinuous when
you go from a 24 hour day to a 24 hour night.

 

Jack Aubert

Falls Church Virginia 

 

   

 

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of Roger Bailey
Sent: Saturday, March 24, 2012 11:04 PM
To: Sundial List
Subject: Equinox Derivative: dx/dt Sin x = Cos x

 

At the equinox, the sun crossed the equatorial plane and the solar
declination passed through zero. What we all experienced each day was a
rapid change in the length of the day so we can now have breakfast and
dinner in daylight. No more candlelight dinners! You may have noticed how
rapid the solar changes have been, increasing the length of the day and the
altitude of the sun. Why is the change so rapid at the equinox and so slow
at the solstices?

 

A mathematician might answer by saying "dx/dt Sin x = Cos x", the derivative
of a sine wave is a cosine. Here most of us would go blank but this is a
concise description of what is happening. The derivative is a measure of the
rate of change. Solar declination is pretty well described by a sine wave,
the familiar curve of AC electrical current and so many circular oriented
phenomenon. At the equinox, the solar declination is zero. We could start
the sine wave description here at the equinox zero. The cosine is just like
the sine wave but displaced by 90°, one quarter of the full cycle, at a
maximum when the sine is at a minimum. dx/dt Sin x = Cos x, so when the sine
wave of solar declination is at its minimum, the derivative, the rate of
change, the cosine is at its maximum at the equinox, and the minimum at the
solstices.

 

Enjoy the rapid change to longer days as we enter spring and approach the
long slow days of summer near the solstice. 

 

Regards, Roger Bailey

 

Walking Shadow Designs

www.walkingshadow.info 

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RE: sundial Digest, Vol 72, Issue 11

[Jack Aubert]

Children learn at a fairly young age - at least I did -- that the earth and
planets revolve around the sun and we learn to take a God's eye view of the
solar system.   We see this depicted in hundreds of pictures.
Unfortunately, this knowledge, while true, is quite removed from our
experience of sunrise, sunset, and seasonal changes.  These things were
explained in the textbooks,  but I found it difficult to do the mental
spatial translation needed to place myself on the spinning earth and relate
this to what I saw in the sky.  I can do it if I make an effort but it is
not easy and I cannot easily hold that picture in my head for a day's
revolution, let alone a year's elliptical orbit.

 

I came to learn about sundials because I wanted a better and more intuitive
understanding of what I had seen at different latitudes and different
seasons.  I believe that the geocentric perspective and heliocentric
perspectives are geometrically equivalent but the geocentric perspective is
more useful for understanding the days and the seasons than the heliocentric
one.   

 

Eppur se muove.

 

Jack.

 

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of Simon [illustratingshadows
Sent: Tuesday, December 13, 2011 12:35 PM
To: and...@lucastes.co.uk; 'Bill O'Neill'; sundial@uni-koeln.de
Subject: Re: sundial Digest, Vol 72, Issue 11

 

Andrew Pettit, and Mike Shaw espouse views that I support. The map is not
the territory, which in this case means that what actually happens and what
we say happens do not match. And if it is easier to understand a sundial by
saying that the sun moves across the sky, especially since that is what we
see, why on earth (sorry for the pun) complicate it when complicating the
matter adds nothing at all to the basic understanding.

 

What I say is that while the earth orbits the sun, which is the basis for
explaining the ecliptic, EOT, etc; for purposes of dial plate design, it is
simpler to say the sun orbits the earth. I see no drawbacks in that
philosophy.

 

Perfection will never happen, it will only be approached. Each solution to a
problems is always the basis for the next problem. Ease of understanding in
this over complicated world is probably a benefit. Avoid confusing an
accurate display with accuracy, a digital clock that is set incorrectly is
of little use.

 

Simon

 

 

Simon Wheaton-Smith
www.illustratingshadows.com
Silver City, New Mexico W108.2 N32.75 and
Phoenix, Arizona, W112.1 N33.5

From: Andrew Pettit 
To: 'Bill O'Neill' ; sundial@uni-koeln.de 
Sent: Tuesday, December 13, 2011 9:45 AM
Subject: RE: sundial Digest, Vol 72, Issue 11

I endorse all that Mike Shaw has said.

My understanding is that it's easier when trying to explain such concepts as
sundials and the "Equation of Time" it is "better" to regard the Earth as
stationary ~ just as the ancient astrologers did. The motion of the earth
around the sun is important in explaining the motion of the planets.

Philosophically the heliocentric system is to be preferred ~ until we need a
frame of reference based on galactic or intergalactic co-ordinates!

Which takes me back to Mike's point!

Hope that this helps. No doubt somebody will put my hat straight if it
doesn't.

Andrew

-Original Message-
From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of Bill O'Neill
Sent: 13 December 2011 12:03
To: sundial@uni-koeln.de
Subject: Re: sundial Digest, Vol 72, Issue 11

Hi All:
Why do people in the 21st century incorrectly continue to say "the sun
moves" across the sky?
We know the sun is generally and at all times in the same spot.
The truth, as we know and accept, is the earth moves. All of the phenomena
that happens because of the daily rotation and the year long trip around the
orbit is fascinating and proves how wrong was the idea that the sun moves.
It's not that our eyes give wrong information but that the mind came to
very wrong conclusions because of wrong conclusions about the information. 
Wrong ideas are serious and to be avoided. Wrong ideas about the moving
earth and stationary sun got Bruno burned at the stake and Galileo thrown in
prison but the truth about the universe finally came out.
Perhaps it's easier to explain to children that the sun is moving but why
not explain to them as early as possible that the sun is in the same spot,
just like everything stays in the same spot as they move? They would grasp
the idea that shadows of the same things are different depending where they
are on the globe. They would learn the correct way to think about so many
phenomena, especially about sundials, instead of the age-old wrong ways.

Regards and enjoy the coming solstice.
Bill O'Neill
Holland, PA. USA

--
From: 
Sent: Tuesday, December 13, 2011 6:00 AM
To: 
Subject: sundial Digest, Vol 72, Issue 11

> Send sundial mailing list submissions to sundial@uni-koeln.de
>
> To subscribe or unsub

RE: sundial Digest, Vol 72, Issue 11

[Jack Aubert]

Eppur se muove! 

:-)

Jack Aubert

-Original Message-
From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of Bill O'Neill
Sent: Tuesday, December 13, 2011 7:03 AM
To: sundial@uni-koeln.de
Subject: Re: sundial Digest, Vol 72, Issue 11

Hi All:
Why do people in the 21st century incorrectly continue to say "the sun 
moves" across the sky?
We know the sun is generally and at all times in the same spot.
The truth, as we know and accept, is the earth moves. All of the phenomena 
that happens because of the daily rotation and the year long trip around the

orbit is fascinating and proves how wrong was the idea that the sun moves.
 It's not that our eyes give wrong information but that the mind came to 
very wrong conclusions because of wrong conclusions about the information. 
Wrong ideas are serious and to be avoided. Wrong ideas about the moving 
earth and stationary sun got Bruno burned at the stake and Galileo thrown in

prison but the truth about the universe finally came out.
Perhaps it's easier to explain to children that the sun is moving but why 
not explain to them as early as possible that the sun is in the same spot, 
just like everything stays in the same spot as they move? They would grasp 
the idea that shadows of the same things are different depending where they 
are on the globe. They would learn the correct way to think about so many 
phenomena, especially about sundials, instead of the age-old wrong ways.

Regards and enjoy the coming solstice.
Bill O'Neill
Holland, PA. USA

--
From: 
Sent: Tuesday, December 13, 2011 6:00 AM
To: 
Subject: sundial Digest, Vol 72, Issue 11

> Send sundial mailing list submissions to
> sundial@uni-koeln.de
>
> To subscribe or unsubscribe via the World Wide Web, visit
> https://lists.uni-koeln.de/mailman/listinfo/sundial
> or, via email, send a message with subject or body 'help' to
> sundial-requ...@uni-koeln.de
>
> You can reach the person managing the list at
> sundial-ow...@uni-koeln.de
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of sundial digest..."
>
>
> Today's Topics:
>
>   1. Re: Alternative mapping sites (Richard Mallett)
>   2. the sun is out right now in Seattle! -  live webcam view of
>  large sundial (Woody Sullivan)
>   3. Re: Alternative mapping sites (John Pickard)
>   4. Re: Alternative mapping sites (Peter Mayer)
>
>
> --
>
> Message: 1
> Date: Mon, 12 Dec 2011 17:18:56 +
> From: Richard Mallett <100114@compuserve.com>
> To: "J. Tallman" 
> Cc: Sundial Mailing List 
> Subject: Re: Alternative mapping sites
> Message-ID: <4ee63780.4070...@compuserve.com>
> Content-Type: text/plain; charset="iso-8859-1"; Format="flowed"
>
> On 18/11/2011 17:02, J. Tallman wrote:
>>
>> Hello All,
>>
>> I've received a lot of gracious help from this list over the 13+ years
>> I have belonged to it, so when I find something I think might be
>> useful to list members I feel compelled to contribute.
>>
>> I'm still looking for alternative mapping/satellite photo sites in an
>> effort to better serve my non-dialist Spectra customers who are not
>> inclined to do remote declination shadow measurements for me. Today I
>> found this one, and it has much more recent photography than Google
>> Earth/Maps for the neighborhood I am seeking, but I still haven't
>> found what I need. It may or may not be useful in all places, but I
>> never heard of it before, so here you go:
>>
>> http://maps.nokia.com
>>
>> Again, if anyone knows of good alternative mapping sites to try when
>> GE is lacking, constructive suggestions would be appreciated...and
>> thank you to all those list members who have taken the time to help me
>> with questions in the past -- I appreciate it!
>>
>> Best,
>>
>> Jim Tallman
>>
>> www.spectrasundial.com
>>
>> www.artisanindustrials.com <http://www.artisanindustrials.com/>
>>
>> jtall...@artisanindustrials.com <mailto:jtall...@artisanindustrials.com>
>>
>>
>>
>> ---
>> https://lists.uni-koeln.de/mailman/listinfo/sundial
>>
>
> I certainly like this one better than the other one.
>
> -- 
> --
> Richard Mallett
> Eaton Bray, Dunstable
> South Beds. UK
>
> -- next part --
> An HTML attachment was scrubbed...
> URL: 
>
<https://lists.uni-koeln.de/mailman/private/sundial/attachments

RE: Lunar Eclipse of 2011 Dec 10

[Jack Aubert]

John,

 

I call that a nebular eclipse, and they are even worse when they are solar!


I sat outside and watched a nebular eclipse of the sun in Morocco in 1994.
It was quite a disappointment.  

 

Jack

 

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of John Pickard
Sent: Friday, December 09, 2011 10:32 PM
To: Brad Lufkin; Sundial Mailing List
Subject: Re: Lunar Eclipse of 2011 Dec 10

 

Hi Brad,

 

The eclipse tonight (Sydney time) has made it to out national news, both on
radio and TV. 

 

http://www.abc.net.au/news/2011-12-09/rain-may-spoil-blood-red-eclipse/37235
64

 

Unfortunately, it's currently totally overcast, with no break expected.

 

 

Cheers, John

 

John Pickard
john.pick...@bigpond.com 

In cloudy northern Sydney (and with nothing worth watching on TV as a
substitute for an eclipse)

- Original Message - 

From: Brad Lufkin   

To: Sundial Mailing   List 

Sent: Thursday, December 08, 2011 6:05 PM

Subject: Lunar Eclipse of 2011 Dec 10

 

I thought some of you might be interested in the upcoming lunar eclipse on
the 10th of this month. I've attached a diagram showing the regions of
visibility of the eclipse.
Brad

  _  

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RE: THE ANCIENT ISLAMIC SUNDIALS - A new book (in Italian)

[Jack Aubert]

Gianni,

 

How can I buy a copy?  I would like one.  Can you take Pay Pal?  

 

Jack

 

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On 
Behalf Of Gianni Ferrari
Sent: Wednesday, December 07, 2011 2:06 PM
To: LISTA INGLESE
Subject: THE ANCIENT ISLAMIC SUNDIALS - A new book (in Italian)

 

After a long time I finally finished  a book dealing with the Islamic sundials 
:  

“LE MERIDIANE DELL’ANTICO ISLAM - Il tempo nella civiltà islamica - 
Caratteristiche, descrizione e calcolo dei quadranti e degli orologi solari 
islamici”

"THE SUNDIALS OF ANCIENT ISLAM - Time in Islamic civilization - Features, 
description and calculation of Islamic quadrants and sundials "

The book is written in Italian language and is the complete redesign of an 
essay on the same topic I wrote in 1998 (150 pg.)

The present text has been completely rewritten and expanded on the basis both 
of new studies and new translations of Arabic astronomical manuscripts 
published in the last 20 years, both of  books and articles on Arabic and Turks 
sundials, both of graphic results obtained with many original programs  and of 
my efforts to "translate" into modern language the methods described by some 
Islamic astronomers who lived about 1000 years ago. 

 

The book has 560 pages and contains 442 footnotes, 560 figures in black and 
white, including 252 original drawings.


The price is 35 € (about 47 $) plus a contribution for postage, currently very 
high (about 10 €  for Europe and 15 € for America - 13 and 20 $ )

 

For those interested  a PDF file (100 kB) with the index of the book and some 
information  can be downloaded from

http://dl.dropbox.com/u/6616660/MERIDIANE%20ISLAM_%20ENGL.pdf

 

and a file with some pages of the book (1.3MB) from 

 

 
http://dl.dropbox.com/u/6616660/Gianni%20Ferrari%20MERIDIANE%20ISLAM_Alcune%20Pagine.pdf

 

My best wishes

Gianni Ferrari

 



 

 

 

-
Ing. Gianni Ferrari 

Lat.44;38,18.5N
Long. 10;56,05.3E
gfme...@gmail.com



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RE: Question about the quadrant instrument

[Jack Aubert]

The English term is “Kufic script” or just Kufic.  

 

http://en.wikipedia.org/wiki/Kufic

 

Apparently Kufic is the oldest of the many calligraphic scripts that Arabic
is written in.To me it looks very modern and reminds me of the 1920’s
art deco movement.   

 

Interesting to learn about the use of letter-number notation in ancient
Arabic – similar to Greek notation – and something that will send me on a
little  research excursion to learn when the decimal place notation and the
original “Arabic numerals” arrived in Arabic.  

 

 

Jack Aubert

 

 

 

 

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of  ??
Sent: Saturday, October 29, 2011 9:29 AM
To: sundial@uni-koeln.de
Subject: Re: Question about the quadrant instrument

 

Hi Gianni,
 
Thank you very much for your valuable reply. I really benefits from your
explanation and figure.
 
The values written on the edges are Arabic letters written with "Kofi's
Handwriting" in Arabic "الخط الكوفي" . every letter indicates a number.
according to this table with regular handwritting:
 
http://www.i3gaz.com/images/Gommal.png
 
and this is the Kofian handwritting:
 
http://www.alqaseda.com/up/uploads/102626ba95.jpg
 
Sorry for my late Reply,,
 
Thanks and Regards,,
 
Muhammad AL-Zubi


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RE: a reverse sundial for the blind

[Jack Aubert]

I have not been able to figure out a plausible way to contort my watch arm
so that 12:00 noon faces my body.  You lost me at step 1.  

Jack Aubert


-Original Message-
From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of Will Vaughan
Sent: Tuesday, October 18, 2011 7:58 PM
To: sund...@rrz.uni-koeln.de
Subject: Re: a reverse sundial for the blind

"Reverse sundial" is a clever phrase to describe the Boy Scout method
of finding north (which I call "Seton's rule" after the organization's
founder), since Seton's rule gives the wrong direction in general for
the same reason that an uninclined equatorial sundial tells the wrong
time in general: the Sun's motion is usually not parallel to the
horizon, so the Sun's hour angle is usually not equal to its azimuth
(plus a constant).

It seems to me, however, that if you inclined your watch, you could
use it as an equatorial sundial and more accurately find north. Here's
a method that might work (but that's also unfortunately less pithy
than Seton's rule): 1) Incline your watch arm at the local latitude
(note: I can't say "in the N/S plane"; this is the tricky part).
Assume 12:00 noon on your watch is facing your body. 2) Split the
difference between the current time and 12:00 noon on your watch. The
angle between this halfway point and 12:00 noon is the hour angle of
the Sun. 3) Awkwardly bend your other arm so that it's sitting on your
watch-wearing arm and pointing towards this halfway point. 4) Rotate
your body until you can feel the sun on your bent arm. (You may have
to tilt your hand if the declination of the sun is extreme). 5) Now
12:00 noon on your watch wearing arm faces south. If you have the
watch-wearing arm held out straight in front of your body you should
be facing north. If you're sighted, steps 3) and 4) are easier: hold
up a finger normal to the watch dial and use it as a gnomon; rotate
until your finger's shadow is opposite the halfway point.

Will
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RE: Most Valuable Sundial?

[Jack Aubert]

Value, schmalue.  

 

But  it appears to be an interesting object, particularly if it really is an
accurate replica of something from the 17th century.  Are there more photos
of it and an explanation of how it works?  At first glance it looks like a
skaphe dial made to be "transparent" by use of a wire grid.  How is it read?
By staring upward?  It would be hard to make out the shadow.  Or do shadows
project down onto the ground?   

 

I have not seen very much about sundials from the Far East, if it is still
OK to call it that.  The only one I can remember offhand is an equatorial
dial at the Imperial Palace in Beijing and I don't know how old that it is.


 

Jack 

 

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of Roger Bailey
Sent: Saturday, July 16, 2011 11:47 PM
To: Sundial List
Subject: Most Valuable Sundial?

 

I happened to come across this obscure link to the Guinness Book of Records
for the "most valuable sundial".

 

http://community.guinnessworldrecords.com/_Most-valuable-sundial/blog/145878
5/7691.html

 

Perhaps, but define value. Is it cost? tons of bronze and gold plating, man
hour of construction? I think not. This sundial is a replica. Perhaps the
original was much more valuable, historically, culturally, scientifically. 

 

Value is not the cost to reproduce. I have designed a sundial to reproduce
at a different location the famous sundial designed by Ibn Al Shatir in
Damascus in 1371, a complex sundial, the first sundial with a polar gnomon.
Mine is a fine sundial but the original is valuable.

 

Are there other nominations for the "most valuable sundial".

 

Regards, Roger Bailey

 

"Life's but a Walking Shadow."  

 

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RE: EoT diagram

[Jack Aubert]

The equation of time was already known to Ptolemy!  See Kevin Karney’s 
excellent article on this subject in the NASS compendium  of December 2009.

Ptolemy’s equation of time was applied to heavenly bodies in general, 
particularly the moon, to explain differences in their return to the same place 
in the sky. 

 

The equation of time, as applied to the sun and the length of the day, was 
known early astronomers, although it remained a technical curiosity in the 
absence of accurate clocks.  Tables of its value were published and refined by 
a number of astronomers, notably by John Flamsteed (1692), who clearly set out 
the two principal causes. 

 

Jack  

 

From: R Wall [mailto:maill...@virginbroadband.com.au] 
Sent: Wednesday, June 22, 2011 7:46 PM
To: Jack Aubert; 'Robert Terwilliger'; clc...@mx.nthu.edu.tw; 
sundial@uni-koeln.de
Subject: Re: EoT diagram

 

Hi Jack,

 

Now that’s interesting. I didn’t know there was such a clock as a 
“Real-time-clock”. I did know that clock makers had included a small sundial 
with their clocks to allow the owner to adjust their clocks. To do that they 
must have had a copy of the Equation Of Time.

 

Thanks very much for the information about the Real-Time-Clock.

 

Roderick Wall.

 

From: Jack Aubert <mailto:jaub...@cpcug.org>  

Sent: Thursday, June 23, 2011 9:17 AM

To: 'R Wall' <mailto:maill...@virginbroadband.com.au>  ; 'Robert 
<mailto:b...@twigsdigs.com>  Terwilliger' ; clc...@mx.nthu.edu.tw ; 
sundial@uni-koeln.de 

Subject: RE: EoT diagram

 

By the late 17th century, as clocks became more accurate, clockmakers struggled 
with the fact that they did not seem to tell true (solar) time.   The Mercure 
de France in 1738 reported that “Many clockmakers find themselves exposed to 
criticisms of their methods by those who claim that their clocks are not 
accurate, since they do not agree with everybody’s favorite neighborhood 
sundial.”  

 

Some attempts were made to force mechanical clocks to adapt to true time.   The 
first true time clocks, designed by the English clockmaker Groton, appeared in 
London around 1692.  William III gave one of them as a present to Charles II of 
Spain.  Clockmakers presented papers to the French Royal Academy of Science on 
the subject. 

 

Several well known clockmakers continued to produce real time clocks:  One of 
these is shown in this illustration http://truesundials.com/real-time-clock.gif 
 from Diderot’s Encyclopedia.  The mechanism included a kidney-piece cam for 
the equation, and a dial with two hands, one golden showing a sun for true time 
and another steel for mean time.  Some of these clocks can be seen at the 
Conservatoire des Arts et Métiers in Paris. 

 

 

Jack

 

 

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On 
Behalf Of R Wall
Sent: Tuesday, June 21, 2011 8:19 PM
To: Robert Terwilliger; clc...@mx.nthu.edu.tw; sundial@uni-koeln.de
Subject: Re: EoT diagram

 

 

Hi Bob,

 

If you have a look at the Jules Audemars Equation of Time watch movement in my 
link you will see a kidney piece. 

 

Roderick Wall.

 

From: Robert <mailto:b...@twigsdigs.com>  Terwilliger 

Sent: Wednesday, June 22, 2011 9:43 AM

To: 'R Wall' <mailto:maill...@virginbroadband.com.au>  ; clc...@mx.nthu.edu.tw 
; sundial@uni-koeln.de 

Subject: RE: EoT diagram

 

Roderick,

 

The eot watch your link produced does not seem to be mechanical – hence no 
kidney piece.

 

Google

movement equation of time watch

 

Then try the images

 

Here’s one

 

http://www.breguet.com/var/ezwebin_site/storage/images/equation-of-time/3646-5-eng-GB/Equation-of-time.jpg

 

Bob

 

  _  

From: R Wall [mailto:maill...@virginbroadband.com.au] 
Sent: Tuesday, June 21, 2011 6:06 PM
To: Robert Terwilliger; clc...@mx.nthu.edu.tw; sundial@uni-koeln.de
Subject: Re: EoT diagram

 

Hi again,

 

This is a good link on EOT and watches

 

http://www.timezone...com/extras/200711101492 
<http://www.timezone.com/extras/200711101492> 

 

Roderick Wall.

 

From: R Wall <mailto:maill...@virginbroadband.com.au>  

Sent: Wednesday, June 22, 2011 7:08 AM

To: Robert Terwilliger <mailto:b...@twigsdigs.com>  ; clc...@mx.nthu.edu.tw ; 
sundial@uni-koeln.de 

Subject: Re: EoT diagram

 

Hi all,

 

After sending my last email. I thought I should have 1st searched the Internet 
before sending it:

 

http://forums.timezone.com/index.php?t=tree 
<http://forums.timezone.com/index.php?t=tree&goto=5710449&rid=0> 
&goto=5710449&rid=0

 

Note: scroll down to the larger photo.

 

Looks as if the outer EOT ring can be adjusted (turned) to have the current EOT 
month at the top 12 o’clock position. And there are other “sun” information, 
what I’m not sure.

 

By the way ChiLan, I think your time scale is the wrong way around. “+” should 
be “-“ and “-“ should be “+”.

 

Roderick Wall.

 

 

From: R Wall <ma

RE: EoT diagram

[Jack Aubert]

By the late 17th century, as clocks became more accurate, clockmakers struggled 
with the fact that they did not seem to tell true (solar) time.   The Mercure 
de France in 1738 reported that “Many clockmakers find themselves exposed to 
criticisms of their methods by those who claim that their clocks are not 
accurate, since they do not agree with everybody’s favorite neighborhood 
sundial.”  

 

Some attempts were made to force mechanical clocks to adapt to true time.   The 
first true time clocks, designed by the English clockmaker Groton, appeared in 
London around 1692.  William III gave one of them as a present to Charles II of 
Spain.  Clockmakers presented papers to the French Royal Academy of Science on 
the subject. 

 

Several well known clockmakers continued to produce real time clocks:  One of 
these is shown in this illustration http://truesundials.com/real-time-clock.gif 
 from Diderot’s Encyclopedia.  The mechanism included a kidney-piece cam for 
the equation, and a dial with two hands, one golden showing a sun for true time 
and another steel for mean time.  Some of these clocks can be seen at the 
Conservatoire des Arts et Métiers in Paris. 

 

 

Jack

 

 

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On 
Behalf Of R Wall
Sent: Tuesday, June 21, 2011 8:19 PM
To: Robert Terwilliger; clc...@mx.nthu.edu.tw; sundial@uni-koeln.de
Subject: Re: EoT diagram

 

 

Hi Bob,

 

If you have a look at the Jules Audemars Equation of Time watch movement in my 
link you will see a kidney piece. 

 

Roderick Wall.

 

From: Robert   Terwilliger 

Sent: Wednesday, June 22, 2011 9:43 AM

To: 'R Wall'   ; clc...@mx.nthu.edu.tw 
; sundial@uni-koeln.de 

Subject: RE: EoT diagram

 

Roderick,

 

The eot watch your link produced does not seem to be mechanical – hence no 
kidney piece.

 

Google

movement equation of time watch

 

Then try the images

 

Here’s one

 

http://www.breguet.com/var/ezwebin_site/storage/images/equation-of-time/3646-5-eng-GB/Equation-of-time.jpg

 

Bob

 

  _  

From: R Wall [mailto:maill...@virginbroadband.com.au] 
Sent: Tuesday, June 21, 2011 6:06 PM
To: Robert Terwilliger; clc...@mx.nthu.edu.tw; sundial@uni-koeln.de
Subject: Re: EoT diagram

 

Hi again,

 

This is a good link on EOT and watches

 

http://www.timezone..com/extras/200711101492 
 

 

Roderick Wall.

 

From: R Wall   

Sent: Wednesday, June 22, 2011 7:08 AM

To: Robert Terwilliger   ; clc...@mx.nthu.edu.tw ; 
sundial@uni-koeln.de 

Subject: Re: EoT diagram

 

Hi all,

 

After sending my last email. I thought I should have 1st searched the Internet 
before sending it:

 

http://forums.timezone.com/index.php?t=tree 
 
&goto=5710449&rid=0

 

Note: scroll down to the larger photo.

 

Looks as if the outer EOT ring can be adjusted (turned) to have the current EOT 
month at the top 12 o’clock position. And there are other “sun” information, 
what I’m not sure.

 

By the way ChiLan, I think your time scale is the wrong way around. “+” should 
be “-“ and “-“ should be “+”.

 

Roderick Wall.

 

 

From: R Wall   

Sent: Wednesday, June 22, 2011 6:18 AM

To: Robert Terwilliger   ; clc...@mx.nthu.edu.tw ; 
sundial@uni-koeln.de 

Subject: Re: EoT diagram

 

Hi ChiLian and Robert,

 

Thanks ChiLan, your EOT curve is interesting. I suppose anything to do with 
sundials has a high chance of being invented before as sundials have been 
around for a long time. 

 

Robert, the kidney shape cam in the watch is interesting, is this watch still 
in production and can it be purchased. I’ve never seen a watch with EOT 
indication.

 

Thanks,

 

Roderick Wall.

 

From: Robert Terwilliger   

Sent: Wednesday, June 22, 2011 5:55 AM

To: clc...@mx.nthu.edu.tw ; sundial@uni-koeln.de 

Subject: RE: EoT diagram

 

The equation graph projected on a circle is used as a "kidney piece" cam in a 
watch movement that can indicate the equation.

 

Here is a picture of the gear carrying the kidney piece. It turns once a year.

 

http://people.timezone.com/mdisher/decorte/gyro2/gyro2_3.jpg

 

Bob

 

  _  

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On 
Behalf Of Chiu ?,Chi lian
Sent: Tuesday, June 21, 2011 12:11 PM
To: sundial@uni-koeln.de
Subject: EoT diagram

 

Hi,

I figured out a way to plot EoT curve which I didn't see in sundial books I 
own. 
Diagram is enclosed here.

For a better resolution one, see
http://dl.dropbox.com/u/31382133/EoT%20.png

Best regards,

ChiLian   24.8N 121E

  _  

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

  _  

No

RE: A wristwatch

[Jack Aubert]

I may be missing something, but I think the only way it could actually work
is to use solar power to run software that would contain a standard
time-keeping chip along with software to translate the time and date into a
pseudo-sundial display, which would probably have to use the same technology
as the Kindle uses for it to be visible in sunlight.  It would be way cool
and I would love to have one but it would not really be a sundial.  In fact,
you could run it off a lithium battery instead of sunlight and it would even
work work at night.  


Jack Aubert


-Original Message-
From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of Fabio Savian
Sent: Friday, June 10, 2011 5:57 AM
To: Sundial List
Subject: Re: A wristwatch

Hi all

I saw the presentation of the wrist watch reported by Darek and I realized 
the watch is on sale in an italian watch shop, it is one of the most 
important watch shop in Italy and it is in Milan where I live.
The watch is called 'Diana', it is a project of an italian designer, Tommaso

Ceschi, it is produced only for this shop of Milan.
I call Pisa (the watch shop) to have other info, the director explained me 
that at the moment it is a concept. The project had been presented during 
'Salone del Mobile' on april, the Design Week in Milan, and the project of 
this watch was supported by Pisa.
The watch may become an object on sale but at the moment it isn't sure and 
they don't know wich kind of functions might have the watch.
Design Week report the watch won some awards but it might show the time with

a digital led display visible when switched on.

It is an interesting idea but probably it will not become what we imagine.

ciao Fabio

Fabio Savian
fabio.sav...@nonvedolora.it
Paderno Dugnano, Milan, Italy
45° 34' 10'' N   9° 10' 9'' E
GMT +1 (DST +2)
- Original Message - 
From: "John Pickard" 
To: "Dariusz Oczki" ; "Sundial List" 
Sent: Friday, June 10, 2011 5:09 AM
Subject: Re: A wristwatch


> Good morning Darek,
>
> Thanks for the post, it is a FABULOUS sundial, I want one for Christmas! 
> Far better than a Patek Philippe, or my old Fossil sundial watch which I 
> bought many years ago in Canada.
>
> Does anyone on the List know if they are actually being made and sold, or 
> is it just a concept?
>
>
> Cheers, John
>
> John Pickard
> john.pick...@bigpond.com
> In cold and cloudy Sydney, Australia
>
> - Original Message - 
> From: "Dariusz Oczki" 
> To: 
> Sent: Friday, June 10, 2011 6:57 AM
> Subject: A wristwatch
>
>
>> Dear Diallists
>>
>> I do not recall here a talk about wrist sundials and particulary about 
>> the one below.
>> However please forgive me if I'm mistaken.
>>
>> Here you will find a presentation of an interesting portable dial:
>>
http://flippies.com/adflipoff/diana-a-wristwatch-concepting-the-ancient-sund
ial-system/
>>
>> -- 
>> Best regards
>> Darek Oczki
>> 52N 21E
>> Warsaw, Poland
>>
>> GNOMONIKA.pl
>> Sundials in Poland
>> http://gnomonika.pl
>> ---
>> https://lists.uni-koeln.de/mailman/listinfo/sundial
>>
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
> 

---
https://lists.uni-koeln.de/mailman/listinfo/sundial


---
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RE: sundial /Jacopo de'Benci

[Jack Aubert]

Yes, it is clearly meant for a polar axis gnomon.   The hour lines are
symmetrical with 6 and 6 crossing at the root of the gnomon so it is meant
to be directly south-facing.   However the hour angle lines do not appear to
be accurate for any latitude.  Iif you measure the hour angles and try to
calculate a latitude, the dial is not consistent.   If the 11-12 hour angle
is correct for 41.4 degrees, then the 6-7 hour angle is too small.  If the
6-7 angles is correct for 53 degrees, then the 11-12 hour angle is too  big.
The errors are on the order of 2 or 3 degrees, which is a lot.   

 

It could possibly be “authentic” in the sense that it was designed and made
when as claimed but it has the wrong kind of gnomon, and even if the gnomon
were corrected it would tell time very badly no matter where it is placed.


 

Jack

 

 

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of John Carmichael
Sent: Monday, May 30, 2011 10:56 AM
To: 'Sundial List'
Cc: i...@mediadesign.me
Subject: FW: sundial /Jacopo de'Benci

 

Hi Jan- I’m forwarding your letter and my comments to the Sundial List.
Perhaps the sundial experts in our group can help you more than I can!

 


___

 

Hello Dialists:

 

I received this letter inquiring about an old European sundial.  I’m not an
expert on these things, so I’m forwarding the letter to you guys.  I’ve
never heard of the maker- Jacopo de’ Benci  whose name is inscribed on the
dial.

 

Looking at the enlarged photo of it at
http://www.mediadesign.me/pollaiuolo/images/sonnenuhr-jacopo-de-benci-4.jpg 

you can see it has a perpendicular rod gnomon, implying that at first glance
it is a nodus-based design.   But the location of the rod seems to be
incorrectly located at the convergence of the hour lines.  I’m thinking that
this dial was not designed to have a perpendicular gnomon.  It should have
an angled polar axis gnomon (an angled rod or a triangular sheet).  Perhaps
the rod was added to the original attachment hole after the original polar
axis gnomon fell off at an earlier date.

 

Does my analysis seem correct?

 

Please copy your replies to Jan K. Botor at i...@mediadesign.me

 

 

Thx

 

John C.

 

 

From: info-mediadesign [mailto:i...@mediadesign.me] 
Sent: Monday, May 30, 2011 2:45 AM
To: jlcarmich...@comcast.net
Subject: sundial /Jacopo de'Benci

 

Dear Mr Carmichael.

 

Mrs. Monika Leonhardt, M.A. (Uhrenmuseum Beyer Zürich) kindly provided me
with your contact details.  

 

I am currently trying to investigate into the origin of this sundial and  I
kindly ask you for your opinion as an expert about  this piece of applied
art and your suggestion if it could possibly be authentic. My personal
opinion is that it is a copy of something made in the 19th Century but I can
not locate anything similar whether in books nor in the whole internet.

 

I put the details that I know, a summary of suggestions I received 3rd hand
and high-resolution pictures at the following link:

http://www.mediadesign.me/pollaiuolo/index.html

 

It is my intention to give it to an department for dendrochronical and
spectroscopic analysis, as I got various  information that differs widely
regarding  the possible age and origin.  It is starting with suggestions,
placing it around the early 19th century and goes as far as it was possibly
an early work by Pollaiuolo at the goldsmith “Ghiberti”  where Jacopo de’
Benci  was apprentice for Metalwork.

That is well a wide range for speculations so, the coming analysis will
place the object in a probable timeframe, I hope . 

 

I want to thank you in advance for your effort and It would be really nice
to hear your opinion and if a scientific analysis would be advisable.

If it is of interest, as  the photographs are may not sufficient  I would be
glad to provide you with the original instrument for further research. 

 

 

With kind regards, 

 

Jan K. Botor

 



  logo

Hauptstr.40
25704 Meldorf
T  0178-7732125

  i...@mediadesign.me
  www.mediadesign.me

 

 

 

 

<>---
https://lists.uni-koeln.de/mailman/listinfo/sundial

RE: sundial /Jacopo de'Benci

[Jack Aubert]

I am reposting this message that for some reason exceeded the size limit:

 

 

Yes, it is clearly meant for a polar axis gnomon.   The hour lines are
symmetrical with 6 and 6 crossing at the root of the gnomon so it is meant
to be directly south-facing.   However the hour angle lines do not appear to
be accurate for any latitude.  Iif you measure the hour angles and try to
calculate a latitude, the dial is not consistent.   If the 11-12 hour angle
is correct for 41.4 degrees, then the 6-7 hour angle is too small.  If the
6-7 angles is correct for 53 degrees, then the 11-12 hour angle is too  big.
The errors are on the order of 2 or 3 degrees, which is a lot.   

 

It could possibly be "authentic" in the sense that it was designed and made
when as claimed but it has the wrong kind of gnomon, and even if the gnomon
were corrected it would tell time very badly no matter where it is placed.


 

Jack

 

 

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of John Carmichael
Sent: Monday, May 30, 2011 10:56 AM
To: 'Sundial List'
Cc: i...@mediadesign.me
Subject: FW: sundial /Jacopo de'Benci

 

Hi Jan- I'm forwarding your letter and my comments to the Sundial List.
Perhaps the sundial experts in our group can help you more than I can!

 


___

 

Hello Dialists:

 

I received this letter inquiring about an old European sundial.  I'm not an
expert on these things, so I'm forwarding the letter to you guys.  I've
never heard of the maker- Jacopo de' Benci  whose name is inscribed on the
dial.

 

Looking at the enlarged photo of it at
http://www.mediadesign.me/pollaiuolo/images/sonnenuhr-jacopo-de-benci-4.jpg 

you can see it has a perpendicular rod gnomon, implying that at first glance
it is a nodus-based design.   But the location of the rod seems to be
incorrectly located at the convergence of the hour lines.  I'm thinking that
this dial was not designed to have a perpendicular gnomon.  It should have
an angled polar axis gnomon (an angled rod or a triangular sheet).  Perhaps
the rod was added to the original attachment hole after the original polar
axis gnomon fell off at an earlier date.

 

Does my analysis seem correct?

 

Please copy your replies to Jan K. Botor at i...@mediadesign.me

 

 

Thx

 

John C.

---
https://lists.uni-koeln.de/mailman/listinfo/sundial

RE: [UK interest only] Sundial for Sale £245,000

[Jack Aubert]

My reaction was:

 

A pub with a sundial and something called a “pothole” complete with winch to
lower you into it!   Is a pothole full of ale?  Wow.  The UK does it again!

 

Jack

 

 

 

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of Richard Mallett
Sent: Sunday, May 29, 2011 4:41 AM
To: Tony Moss
Cc: sundial@uni-koeln.de
Subject: Re: [UK interest only] Sundial for Sale £245,000

 

On 29/05/2011 09:21, Tony Moss wrote: 

On 28/05/2011 20:08, Ian Maddocks wrote: 

hi 

 

Just found a sundial for sale on the internet

BSS No 0682 in Low Bentham Yorkshire   Vertical Decliner

a snip at £245000

although included in the price is a 3 bed detached house / pub called the
Sun Dial Inn!

http://www.rightmove.co.uk/property-for-sale/property-32307221.html

A must for any BSS member / real ale fanatic

 

(I am off down Gaping Gill cave tomorrow which is a few miles away and was
just checking out a few dials to see on the way)

 

Ian Maddocks

Chester, UK

 

Hi Ian,
  Been there, done that! Great experience!  I didn't realize that
there can be streams cascading down the pothole too so take a waterproof
coat with you to avoid a soaking as the winch lowers you down into the
darkness on that 'bosun's chair'.   

Tony Moss





 
 
---
https://lists.uni-koeln.de/mailman/listinfo/sundial
 


I started reading that, and thought you were talking about the pub at first
:-)




-- 
--
Richard Mallett
Eaton Bray, Dunstable
South Beds. UK
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

RE: Analemmatic dials at schools ?

[Jack Aubert]

I agree with what I understood to have been the point of Claude’s initial 
comment:  Analemmatic sundials are not very good for pedagogical purposes.  It 
is true that they are often pitched to children and put in parks or 
playgrounds.  A child can be briefly diverted by the fact that if he stands on 
the name of the month, the shadow of his head will point more or less toward 
the same time as his watch – or these days, maybe his cell phone—but the 
mechanics and geometry that makes it so are quite daunting.   Without a polar 
gnomon, there is no understandable link to the daily rotation of the celestial 
sphere that carries the rising and setting sun.   Moving the base of the shadow 
seems like an arbitrary trick designed to make the numbers come out right.   I 
barely understand how they work myself, and can only do so by moving to an 
uncomfortable level of geometric abstraction where I lose track of the north 
pole and the ecliptic.  I think it is way too much to expect a child to be able 
to grasp the relationship between an analemmatic dial and the basics of 
celestial motion that should be the point of the exercise.

 

I think Tony’s demonstration dial gives an excellent explanation of how the sky 
and the sun relate to the sundial and also how different types of dials relate 
to each other.Instead of adjusting the dial to take account of daylight 
saving time it is more instructive for a child – or an adult – to learn that 
there are three reasons that solar time is not the same as clock time.   It is 
good to be reminded that clock time is arbitrarily shifted twice a year for 
summer time, and maybe to reflect on whether this is  useful or not.   
Similarly, the longitude adjustment – or lack thereof – is a good introduction 
to time zones and why we have them.  Both of these concepts are interesting, 
straightforward, easily understood, and worth knowing.The final equation of 
time adjustment to go from solar time to mean time can be taken on faith.  Most 
people are  satisfied by a vague explanation that this is a consequence of the 
earth’s tilt and elliptical orbit without wanting to understand the exact 
mechanics.   

 

Jack

 

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On 
Behalf Of Claude Hartman
Sent: Sunday, April 24, 2011 5:40 PM
To: Willy Leenders; sundial@uni-koeln.de
Subject: Re: Analemmatic dials at schools ?

 

Thank you Willy.  That is indeed the type of graphic that is needed.
Frans Maes is to be complimented for this diagram approach to explaining the 
principle.

In contemplating this diagram, I think it is important to point out that the 
ellipse is not a shadow.  
What then is the reason that the shadow of the vertical rod falls on the 
projection of the hour point on the ellipse?

I think the answer is best pointed out by noting that the sun's ray and the 
vertical rod define a plane.   
The shadow of the vertical rod must also lie in this plane (it is the "shadow 
plane" of the vertical rod).  
Hence the vertically projected hour point and the shadow of the vertical 
coincide.

It can also be pointed out with the aide of this diagram that the shadow of the 
polar gnomon does not lie in this plane.
Furthermore its shadow would not pass through any hour point other than noon.  
Thus the difference in operation of these two dials is made obvious.   
This can be used to find true North if both are combined in some way.  
This is done in the many "Sun Compass" devices discussed just recently.

I wonder how many teachers would be able to demonstrate these relationships on 
the site of a analemmatic dial?




On 4/24/2011 1:05 PM, Willy Leenders wrote: 

Engels

▼

[Vertaal]

Een tekst of webpagina vertalen 

Bedoelde u: Clude beweert dat de zonnewijzer de productie is van een polaire 
zonnewijzer

[ ]

Typ tekst of een websiteadres of vertaal een document. 
 

Annuleren  

[  ]

Luisteren

Fonetisch lezen


Vertaling van het Nederlands in het Engels


Clude claims that the sundial is the projection of a polar sundial

 

See on the website of Frans Maes, click on  The 
  principle 
of the analemmatic dial

 

Op 23-apr-2011, om 21:24 heeft Claude Hartman het volgende geschreven:





I would like to question the instructional qualities of analemmatic sundials.

Unlike Tony Moss' 'Multi-dial', it is my view that there is only one 
relationship easily illustrated - the projection of a polar dial on to a 
horizontal surface is an ellipse with corresponding hour points.  It is 
extremely difficult why (or how) a vertical person or staff casts a shadow to 
these points.

I am afraid that the instruction falls into rote learning of procedure like so 
many sundial kits  (and much of pedagogy).  I do not know what the underlying 
motivation was for "that part of the UK National Curriculum".

RE: part 2 of longitude correction

[Jack Aubert]

This has all been very instructive.  I am not a complete beginner, but have
to confess that I was under the impression that rotating the dial plate with
respect to the fixed gnomon was sufficient.  Somebody once told me I could
do this and I never really thought about it.  If you actually think about
the longitude correction, it does become obvious that just rotating the dial
plate is not going to be right.  

 

For any dials I have made, I either used one of the programs like Shadows
Pro or Orologi Solari  to include a longitude correction, or more
frequently, now, I use a delta cad macro and keep uncorrected solar time.
I agree with Willy Leenders that sundials should tell solar time.   I have a
watch that can tell me mean time, but it has ceded to my celphone which is
even better.

 

Thanks for the question and thanks for the good answers.  I keep learning
things here, many of which I should already know but somehow missed.  

 

Jack

  

 

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of John Carmichael
Sent: Wednesday, February 09, 2011 6:46 PM
To: 'Donald Christensen'; sundial@uni-koeln.de
Subject: RE: part 2 of longitude correction

 

(I hit the wrong button in my last email and it went out without my letter-
sorry!)

 

Hi Donald:

 

I understand your question, because I had this same question years ago when
I was a beginner.

 

The answer is no.

 

To re-phrase your question so that everybody understands it, you are asking
this- When drawing a sundial face, should you simply rotate the normal solar
time hour lines about their center of origin by 3 degrees to obtain a
longitude corrected face?

 

No, you can not do this.  Each hour line has to be calculated and drawn
individually.  This is a common error some beginning dialists make when
designing longitude corrected dials.  I almost made this mistake too once!

 

To help you out (since a picture is worth a thousand words) I drew your
sundial in five minutes using Shadows Pro and sent it you off list the
drawing.  I just didn't want you to make a common mistake.  But verify it
for yourself and don't take my word for it.  That's how you learn!

 

Keep asking good questions!

 

Thanks

 

John

 

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of Donald Christensen
Sent: Wednesday, February 09, 2011 3:52 PM
To: sundial@uni-koeln.de
Subject: part 2 of longitude correction

 

I'm laying out lines for a new dial

I may not have been clear. I don't intend to rotate the gnomen. The dial
will still point true north

By labeling 12:12 as noon and 13:12 as 13:00, I am rotating the hour marks.
My question is,

Is it by an even 3 deg? 

-- 
Cheers
Donald
0423 102 090


This e-mail is privileged and confidential. If you are not the intended
recipient please delete the message and notify the sender. Un-authorized use
of this email is subject to penalty of law.
So there!

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RE: New Stained Glass Sundial- Finished!

[Jack Aubert]

Beautiful!  

Particularly the traditional fly.  

 

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of John Carmichael
Sent: Saturday, January 29, 2011 2:50 PM
To: sund...@rrz.uni-koeln.de
Cc: Glass List
Subject: New Stained Glass Sundial- Finished!

 

Hello Friends:

 

My new stained glass sundial is finally finished!  The client picks it up
next week and will permanently install it in his living room window at his
home in Boulder City Nevada.  It measures 2 x 3 ft (or 61 x 91 cm). It took
twice as much time to complete as I thought it would.  But I wanted to take
my time and do a good job because unfortunately, the opportunity to make and
sell one doesn't come along very often. I'm particularly proud of the
stained glass artwork and the magnetic gnomon attachment.  I think it is one
of my best sundials.

 

For attaching the gnomon to the sundial window, I tested twenty different
neodymium magnets with different configurations, but this design worked best
for this particular window. Special thanks to Dave Bell for his sharing his
knowledge of magnet polarity problems! Choosing the right magnet and the
right configuration is most important.  Some work great, some don't.  (see
gnomon design diagram at:
http://www.flickr.com/photos/jlcarmichael/5387807446/ ) This is a modified
and improved version of the one you have seen. 

 

I hope to write articles about these tests and the construction of the
window for the BSS and NASS journals if I can only find the time!  I'm sure
that some of you will find magnetic gnomons useful for some of your own
sundial projects.

 

You can see the photos of the new dial at:
http://www.flickr.com/photos/jlcarmichael/ 

 

Hope you like it!

 

John

 

John L. Carmichael

Sundial Sculptures

925 E. Foothills Dr.

Tucson AZ 85718-4716

USA

Tel: 520-6961709

Email:   jlcarmich...@comcast.net 

 

My Websites:

(business) Sundial Sculptures: http://www.sundialsculptures.com
  

(educational) Chinook Trail Sundial:
http://advanceassociates.com/Sundials/COSprings/

(educational) Earth & Sky Equatorial Sundial:
http://advanceassociates.com/Sundials/Earth-Sky_Dial/  

(educational) Gnomons, Styles & Nodi:
http://www.flickr.com/groups/1207180@N23/ 

(educational) My Painted Wall Sundial:
http://www.advanceassociates.com/WallDial 

(educational) Painted Wall Sundials:
http://advanceassociates.com/WallDial/PWS_Home.html 

(educational) Stained Glass Sundials: http://www.stainedglasssundials.com
  

(educational) Sundial Cupolas, Towers & Chimneys:
http://StainedGlassSundials.com/CupolaSundial/index.html 

 

 

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RE: New BSS website

[Jack Aubert]

Very nice! Congratulations.  A clean, uncluttered elegant look.  

I see that the list of topics in the left-hand column is alphabetized.  You
might think about re-ordering them by some other criterion like
general-to-specific.  This way, you could put some things like Tony's "how
sundials work" and the glossary and formulae page at the top and things like
"grants policy, restoration advice and mass dials at the bottom.

Jack.

-Original Message-
From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of Richard Mallett
Sent: Friday, November 05, 2010 7:41 PM
To: Sundial List
Subject: New BSS website

The new website for the British Sundial Society is now available at 
www.sundialsoc.org.uk (no need to change your bookmarks) - still a few 
details to be brought up to date, but please let me know what you 
think.  It even seems to work (after a fashion) on mobile devices, so 
you can take it with you on your sundial trips :-)

-- 
--
Richard Mallett
Eaton Bray, Dunstable
South Beds. UK


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RE: Sundials/BHI

[Jack Aubert]

I hesitate to jump in here, not knowing the background, but would like to
offer two observations.  

 

I have been working on photo-engraved brass dials under the generous
long-distance tutelage of Tony Moss, starting from a video that he presented
at our most recent NASS conference.  Using this method, virtually any
artwork that can be rendered through a drawing program, including the figure
8 analemma  can be etched into a brass plate.  The method requires some
equipment and chemicals, but the investment is extremely modest compared to
a CNC machine and the results can be quite spectacular.  (“Did you actually
make that yourseif?”)  I also have used, and still use, François Blateyron’s
excellent shadows program, but have found that for actually laying out the
artwork for a working dial including a noon gap and other dial furniture one
really needs to transfer everything to a drawing program for manipulation.


 

The term “analemmatic sundial” is generally used to refer an elliptical
dial, typically laid out on the ground where the moveable gnomon (a person)
casts the shadow.   An engraved analemmatic dial would therefore call for an
ellipse, as noted by Julian Greenberg, rather than a figure 8 analemma
design, although a figure 8 analemma can be incorporated into an analemmatic
dial for reference.  It would be unusual to engrave an analemmatic dial into
a brass garden dial because of the moveable (and stealable) gnomon, but John
Charmichael has made some very beautiful analemmatic dials engraved in
sandstone suitable for use in a private setting where the gnomon can be put
away and/or replaced.

 

Are you engraving in metal?  Stone?

 

 Jack Aubert 

 

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of Douglas Bateman
Sent: Sunday, June 13, 2010 5:11 AM
To: julian greenberg
Cc: Sundial List
Subject: Re: Sundials/BHI

 

Dear Julian,

 

I look forward to see the pictures in due course.

 

The analemma, however, does not have a nice mathematical curve (at least as
far as my maths goes) nor based on any ellipses.  Some of my really high
tech friends have CAD software that would take the coordinates of each point
and transfer into the CNC machine - all done!

 

Otherwise make a template smoothed by hand through the points for the
engraver to follow.

 

Regards, Doug

 

PS  Are you aware of the useful internet chat group  sundial@uni-koeln.de  ?

 

On Jun 13, 2010, at 00:56, julian greenberg wrote:

 






Enjoyed your talk on Thursday night.We spoke afterwards.

Will find some pictures of my dials and send them to you.

My next project will be an Analemmatic dial.

However this will be difficult to make, as I have no way of engraving
elipses.

I use Waugh and Rohr's books as reference.I also use the french "shadows"
software.

Regards

Julian

 

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RE: how italian hours

[Jack Aubert]

I have been thinking the same thing.

That slate dial is strikingly beautiful and I like the idea of using a
completely different type of hour that does have to offer any excuses for
not being the same as what is on one's watch.  Frank King's narrative write
up answered one of my questions.  I had assumed that Babylonian hours must
be something from Babylon and therefore unequal hours but apparently they
came into vogue along with "Italian hours" after the arrival of mechanical
clocks.  They are equal hours.  

I was struck by the fact that the Italian and Babylonian hours coincide
(cross each other) at the equinox line but not at the solstice lines.  After
staring at the two types of hours, which seem like they should be
reciprocal, so to speak, for a while I was not able to come to any intuitive
understanding of how they work and why they are not symmetrical. 

The only detailed instructions I have been able to find for construction of
Italian hour dials is Mac Oglesby's paper on the dial he made for Moore's
Field: http://www.mysundial.ca/files/H2SSManual040801.pdf.  This method uses
trigonometry and requires calculating the sun's azimuth among other things.


I have no objection to using trig or computer software, but I wondered if
there any geometry-based methods for laying out Italian/Babylonian hours?
Were older dials with Italian and Babylonian hours always laid out using
trigonometry?  Also I wonder about combining a vertical sundial with a polar
gnomon with a nodus for Italian/Babylonian hours.  It might be too cluttered
and complex to be worthwhile in practice but I wonder about the relationship
if any between the two types of dial  

Jack


-Original Message-
From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of Frank Evans
Sent: Monday, March 29, 2010 6:47 AM
To: Sundial
Subject: how italian hours

Greetings, fellow dialists,
Following the pictures of the fine dial of Frank King in Selwyn College, 
Cambridge (congratulations) I began to wonder how it was laid out. Most 
of the commonly consulted books on dial construction (in English), 
Waugh, Mayall & Mayall, Cousins, etc. do no more than glance at Italian 
and Babylonian hours. Only Rohr has some account. His practical method 
appears to be to find the time and nodus point of sunrise and sunset at 
the solstices, count the hours back from them and join the winter and 
summer nodus points for each hour. This seems a pretty journeyman's 
procedure (nothing wrong with that) but I wonder if there is some more 
sophisticated method.

Also, the assumption seems to be made that sunrise and sunset occurs 
when the altitude of the sun's centre is zero. This is far from sunset 
in any practical sense. Any comments, please?
Frank 55N 1W


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RE: DST Misconceptions

[Jack Aubert]

How about the misconception that it saves energy.  I have never seen any
serious scientific study that supports that theory which is implausible
given energy use patterns in the 21st century.  

 

Jack 

 

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of John Carmichael
Sent: Sunday, March 14, 2010 11:39 AM
To: 'Sundial Mailing List'
Subject: DST Misconceptions

 

Every year at this time, you hear about people who actually believe that one
hour of time is lost.  It's as if they think that Daylight Saving Time works
like a Time Machine.

 

Case in Point:

 

Yesterday, while watching a respected national news weather report, the
weatherman was standing on a beach in New Jersey reporting on the horrible
windy weather.  He was commenting on how the ocean waves were eroding the
beach.

 

He actually said this:

 

"Thank goodness for Daylight Saving Time, because that means that there will
be one less hour of beach erosion!"

 

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RE: dalemain stolen dial

[Jack Aubert]

Such a shame that we cannot have sundials inside.  

What we need is for somebody to develop a motor-driven, geared apparatus
that will move an electric through a path that picks up all the relevant
celestial motions.   

Jack

-Original Message-
From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of Richard Mallett
Sent: Saturday, November 21, 2009 7:42 AM
To: Frank King
Cc: Sundial
Subject: Re: dalemain stolen dial

Frank King wrote:
> Richard Mallett wrote:
>
>   
>> ... dials often become completely unreadable
>> when left outside...
>> 
>
> They do indeed but...
>
> ...a sundial which isn't out in the sun is no
> more useful than a clock without hands :-)
>
> Frank King
> Cambridge, U.K.
>
>
>   
If I had a clock worth £60,000 and a replica worth £500 I would take 
more care of the more expensive original, wouldn't you ?

-- 
Richard Mallett
Eaton Bray, Dunstable
South Beds. UK

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RE: Analemma origins.

[Jack Aubert]

I think this was really a two part question.  

 

The first question is the historical origins of the discrepancy between
apparent and mean solar time.  

I look forward to reading Kevin Karney's discussion of Ptolemy's treatment
of this which should answer the first question.  But there is a distinction
between the equation of time itself and the use of the figure 8 analemma to
represent it.  

 

John Carmichael rephrased the second question more explicitly:  "Could the
analemma have been discovered without the empirical methods using just
astronomy and math."  

 

Fred Sawyer writes:  "The figure 8 is usually attributed to Grandjean de
Fouchy."  Fred's encyclopedic knowledge can be taken as authoritative with
respect to the first appearance the figure.  But the coordinate system that
generates the figure 8 plot is virtually unique and is not something that
one would normally come up with to display any arbitrary time series, so I
think it must have been discovered empirically either by Grandjean de Fauchy
himself or by others who lived before him.  Grandjean de Fauchy lived from
1707 to 1788,  well into the clock era.  

 

Could the figure have been "discovered" without a clock (I am counting a
clepsydra as a clock) and are there any antecedents that predate the
mechanical clock era?   

 

Jack

 

 

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of Fred Sawyer
Sent: Saturday, November 14, 2009 11:30 PM
To: Sundial List
Subject: Analemma origins.

 



Sent from my iPod


Begin forwarded message:

From: Fred Sawyer 
Date: November 14, 2009 7:11:18 PM EST
To: John Carmichael 
Subject: Re: Analemma origins.

The next issue of the compendium will have an article by Kevin Karney
showing Ptolemy's treatment of the equation of time - it does not require a
clock.

The figure 8 is usually attributed to Grandjean de Fouchy - perhaps
incorrectly - but this is only a graphical way to display sething that had
been known but not completely understood for centuries.

Fred

Sent from my iPod

On Nov 14, 2009, at 6:58 PM, "John Carmichael" 
wrote:




Hi Tony et all

 

 

Yes, I think you might be on the right track. The discoveor of the analemma

would need to have some sort of a clock that tells Mean Time (constant

time).  Sand clocks, candle clocks and water clocks all keep Mean Time don't

they?  Of these ancient clocks, I'm guessing that the most precise would be

the water clocks.

 

If a sundial nodus shadow was plotted onto a sundial face using a particular

time each day as told by a good water clock, then could'nt an ancient dialst

have been able to draw the analemma on a sundial face using the emperical

method?  The Egyptians had good water clocks.  Couldn't they have discovered

the analemma?

 

Could it be done today with a modern precise water clock?

 

Or could the analemma have been discovered using just astronomy and math

without the emperical method using a nodus, the sun and a clock?

 

John C.

 

 

-Original Message-

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On

Behalf Of Tony Moss

Sent: Saturday, November 14, 2009 4:33 PM

To: Sundial Mailing List

Subject: Analemma origins.

 

Jack Aubert wrote:

 

I recently revised my notes for a sundial talk I was giving which

included a section on the EOT, and its connection with the traditional

figure 8 analemma. I wanted to explain its origin, or at least be able

to answer the question if asked, but have not been able to find any

believable references on how it emerged. I assume that the source of

the figure is simply a "connect the dots" picture of what the sun, or

a gnomon pointer will trace it out over the course of the year

projected onto a surface. But I do not see how the dots can be

generated without using an external non-solar source of time.

 

The Wikipedia article on the EOT has a confusing statement to the

effect that Ptolomey was aware of the variation in the sun's movement

and even devoted a chapter to the subject, but then says that he did

not correctly account for the two sources of variation. Is there any

evidence that the Greeks or Romans ware aware of, and used, the

analemma representation, perhaps generated by reference to a

clepsydra, or did it first appear when mechanical clocks became

prevalent?

 

Jack

 

Did the analemma concept arrive with Huygens and his accurate mechanical

clocks? My guess is that he initially set his clocks by the sundial but

eventually came to realize that the clocks were 'accurate' and the

sundial was varyingly 'out-of-step'. I'd love to have any evidence

surrounding this notion.

 

Tony Moss

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Origin of the Analemma figure?

[Jack Aubert]

I recently revised my notes for a sundial talk I was giving which included a
section on the EOT, and  its connection with the traditional figure 8
analemma.   I wanted to explain its origin, or at least be able to answer
the question if asked, but have not been able to find any believable
references on how it emerged.   I assume that the source of the figure is
simply a "connect the dots" picture of what the sun, or a gnomon pointer
will trace it out over the course of the year projected onto a surface.
But I do not see how the dots can be generated without using an external
non-solar source of time.   

The Wikipedia article on the EOT has a confusing statement to the effect
that Ptolomey was aware of the variation in the sun's movement and even
devoted a chapter to the subject, but then says that he did not correctly
account for the two sources of variation.  Is there any evidence that the
Greeks or Romans ware aware of, and used, the analemma representation,
perhaps generated by reference to a clepsydra, or did it first appear when
mechanical clocks became prevalent?

Jack   
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RE: New Sundial Sculptures Website

[Jack Aubert]

Hi John,  

 

The site looks really beautiful.  Congratulations to you and to your
webmaster.   

 

I wouldn't worry about the Google translator moving the layout.  I checked
several of the languages I can read and the translations are all very
sketchy anyway:  You can understand the meaning enough for practical
purposes, but having text in odd places is not noticeable given the rest of
the oddness.  But that's a function of Google and has nothing to do with the
site itself.   

 

Jack

 

From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of John Carmichael
Sent: Monday, July 06, 2009 3:54 PM
To: 'Sundial List'
Subject: New Sundial Sculptures Website

 

Hello All:

 

My sundial business website webmaster has recovered from a long illness, and
we have completely updated it after two years of no updates.

 

See: Sundial Sculptures: http://www.sundialsculptures.com
 

 

We have made it a little less technical and a bit more artistic and
user-friendly, with lots of new photos and graphics.  We've tested it as
much as we can, so I'm interested to hear if any of you find any problems
with it.  

 

I have noticed on my computer that the new Google translator tool at the top
right of the page sometimes corrupts the Home page layout after language
translation. (It puts text in odd places.) I only see this on my computers.
My webmaster does not see it on his.  So I'm most interested if any of you
have had problems the the Google Translator tool corrupting page layouts,
either on my site or other sites that have this tool.

 

If you have any other comments or suggestions for improving the website, I'd
be grateful to hear them.

 

Thanks,

 

John

 

 

John L. Carmichael

Sundial Sculptures

925 E. Foothills Dr.

Tucson AZ 85718-4716

USA

Tel: 520-6961709

Email:   jlcarmich...@comcast.net 

 

 

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RE: Translations

[Jack Aubert]

The lava strips are made from "lave emaillée" which is different from
"lave":

Extraite dans les volcans d'Auvergne, la lave émaillée est réputée pour sa
dureté. La lave emaillee ne craint pas pas le gel, la pierre de lave
emaillee resiste parfaitement aux UV, la lave émaillée résiste à beaucoup
d'acides, la lave émaillée peut être déclinée en multiples couleurs et
formats jusqu'à 250cm de long pour plans de travail cuisine, plans de
travail salle de bains ainsi que des tables en lave emaillee. Les vasques et
éviers sont en grès émaillé. Les vasques émaillées et les éviers émaillés
sont collés par dessous les plans en lave émaillée.

It is therefore similar to porcelain, but uses stone as a substrate.   In
this instance, the best translation for "lave would have been "enamel"  

As for machine translation, it is helpful when you have no clue or are
dealing with a language where you have zero knowledge.  But so far, the only
way to get a "real" translation is to run it through a human brain.  Machine
translation may eventually be a reality, but not until they perfect
artificial intelligence.  

Learn more languages! There is always time for one more. 

Jack Aubert   

-Original Message-
From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of Frans W. Maes
Sent: Tuesday, June 16, 2009 6:12 AM
To: Steve; robic.joel; Sundial List
Subject: Re: Translations

Dear Steve and all,

Three free translators I sometimes use for websites or short texts, are:
- Babelfish: http://babelfish.yahoo.com/
- Google: http://translate.google.com/
- Prompt: http://www.online-translator.com/

You may try each on the AFP press release:
http://www.google.com/hostednews/afp/article/ALeqM5gFPjvks3c5EemskZkRWhCB-Fu
_IA
and judge the quality (when you read French and English) or see whether 
you get the message. In this case, the photos set the stage for the 
story, so that makes it easier.

For this limited sample, I think Prompt does a slightly better job than 
Google, and Babelfish is last. What do you think, Joël?
Prompt marks the words that were not translated, such as proper names, 
which is handy.

More generally, a simple original, both in terminology and in grammar, 
leads to a better translation. That's why e-mail messages often 
translate badly.

For me, the most important paragraph in this text is how the sundial 
should function:

"Innovation de ce cadran: c'est l'ombre même du parapet projetée sur la 
voûte du barrage qui permet de lire l'heure solaire.
Chaque heure est matérialisée par une "ligne horaire" confectionnée avec 
des plaques en lave émaillée: ocres pour les heures du matin, vertes 
pour celles de l'après-midi. L'heure solaire est connue lorsque l'ombre 
tangente l'une de ces lignes."

which translates into:

Babelfish:
Innovation of this dial: it is the shade even parapet projected on the 
vault of the stopping which makes it possible to read the solar hour.
Each hour is materialized by a “time line” made with plates in enamelled 
lava: ochres for the hours of the morning, green for those of the 
afternoon. The solar hour is known when the tangent shade one of these 
lines.

Google:
Innovation of the dial: the very shadow of the parapet onto the arch 
dam, which allows you to get the solar time.
Each hour is marked by a "line timetable" made with plates in enamelled 
lava: ochers for the morning, green for those in the afternoon. The 
solar time is known when the shadow tangent one of these lines.

Prompt:
Innovation of this face: it is the shadow of the breastwork cast on the 
arch of the dam which allows to read the solar hour.
Every hour is fulfilled by a "line per hour" made with plates in 
interspersed lava: ochres for hours, green for those of afternoon. The 
solar hour is known when tangent shadow one of these lines.

In the original, the most essential word of the entire story is 
"tangente", which apparently is used as a verb: the shadow of the edge 
touches (kisses, osculates) an hour line. This may be an uncommon usage, 
as all three utilities interpret it as an adjective and try to make at 
least some sense out of it.

And I wonder what the lava strips are made of...

Best regards,
Frans Maes



Steve wrote:
> Confrere:
> 
> I am interested in translating email and web 
> pages into English.  I use as example the note 
> from Joel about the Castillon Dam.  The link 
> contained in his email is to a web page in French and so my question.
> 
> I use Eudora for mail and have receded to FireFox 
> version 2.00.18.  However, I have tried various 
> translators with several versions without much success.
> 
> My question.  Does anyone use a translation 
> program for email and the web, with success.
> 
> Thanks
> 
> Steve
> Yorktown VA
> 
> 
&

RE: sundial Digest, Vol 38, Issue 18

[Jack Aubert]

First of all, it is not very civil to start up a political argument on a
list like this.

Second, the sentiment you are reacting to is simply a "tag-line" presumably
attached to all messages sent by Yan Seiner.  Reacting to it is like picking
a fight with somebody who pulls into a parking lot because you don't like
his bumper-sticker.

Thirdly, your conclusion "That is an admission..etc" where you probably
meant to say "That is an accusation..." does not follow logically from the
sentiment expressed by the tag-line. In fact it doesn't even make sense as a
stand-alone thought.  I imagine that the vast majority of mankind lives for
its own happiness and at the same time seeks to avoid punishment.  

Jack
...who does not want to start a flame war, but couldn't let this pass 




-Original Message-
From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On
Behalf Of Bill O'Neill
Sent: Saturday, February 28, 2009 8:17 AM
To: sundial@uni-koeln.de
Subject: Re: sundial Digest, Vol 38, Issue 18

Good that you admit you are out of the sundial domain when you wrote that 
you "like paying taxes because with them I buy civilization".

That is an admission that every other human is un-civilized and instead of 
living for their happiness they seek only to avoid punishment. That's an 
un-civil and inhuman attitude and I'll have no part of it.

- Original Message - 
From: 
To: 
Sent: Saturday, February 28, 2009 6:00 AM
Subject: sundial Digest, Vol 38, Issue 18


> Send sundial mailing list submissions to
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>
> You can reach the person managing the list at
> sundial-ow...@uni-koeln.de
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of sundial digest..."
>
>
> Today's Topics:
>
>   1. Sundials in a dome (Douglas Bateman)
>   2. Variation in Sun's declination (Alex Botkin)
>   3. Solar Eclipse (Yan Seiner)
>   4. .Re: Variation in Sun's declination (Patrick Powers)
>   5. March BSS Bulletin (JOHN DAVIS)
>
>
> --
>
> Message: 1
> Date: Fri, 27 Feb 2009 15:11:46 +
> From: Douglas Bateman 
> Subject: Sundials in a dome
> To: Sundial List 
> Message-ID: <8c914c5c-91ff-41eb-8cc9-163a57d2a...@btinternet.com>
> Content-Type: text/plain; charset="us-ascii"
>
> I have had the enquiry below from a student and I believe the group's
> 'international skills' will provide more answers than I can with our
> lack of such dials in the British Isles.
>
> In response to my initial reply I received the second courteous
> message today, also below.
>
> Regards, Doug
>
> [24 Feb 09] Dear Mr. Bateman
>
> I am an architecture student at studying on astronomical architecture,
> Im looking for examples of domes which act as sundials, Unfortunately
> there isn't much detail about these kinds of domes in the world, I
> wonder if Your honorable could introduce me any resources related to
> this topic.
>
> Sincerely yours
>
> Mohammad Vaez,
> Bachelor of Arts
> Faculty of Fine Arts
> University of Tehran
> Tel. +98-21-26058691
> Email: mv_20...@yahoo.com
>
> [27 Feb 09]
> Dear Mr. Bateman
>
> Thank you for replying to my question, The only example I have found
> is the Pantheon dome which the sun shines from the hole exactly at the
> top on the coffering surface of the dome itself which it is said to be
> a sundial, I will be glad to recieve any technical information from an
> international expert.
> -- next part --
> An HTML attachment was scrubbed...
> URL: 
>
https://lists.uni-koeln.de/mailman/private/sundial/attachments/20090227/c62a
b59e/attachment-0001.htm
>
> --
>
> Message: 2
> Date: Fri, 27 Feb 2009 21:04:39 -0500
> From: Alex Botkin 
> Subject: Variation in Sun's declination
> To: 
> Message-ID: 
> Content-Type: text/plain; charset="iso-8859-1"
>
>
> While on a search for something else, I began noticing that values for the

> declination of the sun seem to vary a great deal.
>
> I am probably not appreciating the derivation nuance of each value, but 
> here are the various sources that gave me pause.  Can one of these be 
> considered "more accurate"?
>
> What's a boy to do?
>
> 1)   Wikipedia, http://en.wikipedia.org/wiki/Solar_declination with 
> reference to a table --  
> http://www.wsanford.com/~wsanford/exo/sundials/DEC_Sun.html
>
> +8?30'   - four year average - September 1
>
>
> 2)  Excel Spreadsheet for COMPUTATION OF THE SCALE OF DATES FOR AN 
> ANALEMMATIC DIAL  @
> http://www.mysundial.ca/tsp/analemmatic_sundial.html
>
> 7.96  -  September 1
>
>
> 3)  http://faculty.physics.tamu.edu/krisciunas/ra_dec_sun.html
> 8: 2: 1 -  September 1 2009
>
>
> 4) 
>
http://www.starsatnight.org/HeadsUp/charts/Declination%20o

RE: David Shayt

[Jack Aubert]

David Shayt's obituary ran today in the Washington Post:

http://www.washingtonpost.com/wp-dyn/content/article/2008/11/11/AR200802
483.html?sub=AR

Jack


-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Fred Sawyer
Sent: Wednesday, November 12, 2008 9:54 AM
To: Sundial List
Subject: David Shayt

I have just learned:

Smithsonian Curator David Shayt died on Nov. 4 of multiple myeloma at
his home in Gaithersburg MD.  David served on the NASS board, was a
planner and host for our 1995 (first) conference held at the
Smithsonian, and gave us a narrated tour of the Latitude Observatory
in Gaithersburg on our 2007 conference.

Fred Sawyer
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RE: Missouri Ottoman Sundial

[Jack Aubert]

I would never have had a reason to visit St. Louis, and am very glad to have
had the excuse.  The botanical garden is, I think, the most beautiful garden
I have ever visited.  As the Guide Michelin would put it “ca vaut le
detour”.  And if you ever do make the detour to the Missouri botanical
garden, Roger’s Ottoman sundial is both beautiful as a piece of stonework
and fascinating for its historical and gnomonical  significance.  You also
get Ron Rinehart’s dial and a schmoyer dial and at least one sculpture
sitting in a bed of (guess what:…thyme).  A triple “vaut le detour” for St.
Louis Missouri.  

 

Jack Aubert.

 

From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Roger Bailey
Sent: Wednesday, August 13, 2008 5:47 PM
To: Sundial Mailing List
Subject: Missouri Ottoman Sundial

 

The Sundial Tour for the NASS conference in St Louis Missouri visited the
Missouri Botanical Garden where three new sundials were on display. There
was a dedication ceremony for Ron Rinehart's  "scientific sundial". See
http://www.scisundials.com/SciSundials/Welcome.html Don Snyder, our local
host, donated a "Schmoyer Sunquest" sundial by Bill Gottesman.  See
http://www.precisionsundials.com/schmoyer.htm  

 

The highlight for me was the Ottoman Sundial I designed and Abraham Mohler
carved. The reoriented dial was completed just in time for the Garden
Members meeting and the NASS tour. This dial with a 28' square marble dial
plate stands 42' high as a centerpiece in the Ottoman Garden. It has two
gnomons and four time systems: The polar gnomon works with the outer scale
to show regular solar time based on 12 noon. The Ezanic dial with a vertical
gnomon shows Babylonian hours based on 12 sunrise, Italian hours based on 12
sunset and Moslem prayer times, Zuhr and Asr. The plinth is now aligned with
the axis of the garden (N 9º E)  and the dials are aligned to the polar
axis. The NASS members can confirm that the dial now accurately shows
correct solar times.

 

I would like to thank NASS members and many on this list who provided
information and advice on this project. It is a beautiful dial that I am
pleased to have the opportunity to provide the design. Abraham Mohler, a
local sculptor in St Louis did an excellent job fabrication the dial and
accurately carving the lines

 

Pictures and further information are available on my website. The direct
link is http://www.walkingshadow.info/Ottoman.html  The whole story is
outlined in my NASS Conference presentation, a 10 MB PowerPoint file. 

 

Enjoy,

 

Roger Bailey

 

"Life's but a Walking Shadow"

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Azimuth of Sunrise - Sunset

[Jack Aubert]

Thank you all for the answer(s) to this little problem and for the 
bread-crumb trail to try to retrace the derivation.


My original question was sparked by wondering about the maximum deviation 
from east-west at the solstice(s) so I could display my erudition and bore 
people with comments like: "The sun rises in the East and sets in the West, 
right? Well, not really.  Actually "


What I had meant about reading the answer directly from the sundial, 
assuming that you already know the time of sunrise,  is that if you were to 
lay the straight edge of a protractor between the root of the gnomon and 
the time of sunrise on the dial face, you could read the deviation from 
east-west where the six o'clock line intersects the protractor scale.   Of 
course, if my sunrise time were taken from the daily newspaper, I would 
have to adjust for longitude.


At my latitude (38.88 north) the formula tells me that on the solstice, 
sunrise/sunset deviates from east-west by 30.74 degrees, which looks like 
it agrees with the protractor method (allowing for the fact that I can't 
actually lay it on the dial without removing the gnomon).


Jack

At 08:28 AM 12/24/2007, Frank King wrote:

Dear Geoff,

Yes, you are absolutely right.  Silly me for not spotting
a trivial simplification!  It is, indeed, much neater to
write:

>  cos(az)=sin(dec)/cos(lat)

This also readily shows that reversing the sign of the
declination results in 180 degrees being added to (or
subtracted from) the azimuth.

It is slightly less obvious that dec+lat and dec-lat
must be in the range -90 to +90 though.

Also...

> ... its comforting to realise that the sun has been
> rising a little bit closer to the north for the last
> couple of mornings.

There is a delightful paradox in this.  What you say
is certainly true but, nevertheless, the (clock) time
of sunrise is still getting later, and the latest
sunrise this year is not for another week.  You will
have to survive Christmas before you can start feeling
comfortable!!

By way of compensation, the evenings have been drawing
out for the past 10 days.

Best wishes

Frank
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Re: Winter Solstice at Newgrange, Ireland

[Jack Aubert]

I have been half-heartedly attempting -- with my shaky grasp of 
trigonometry -- to figure out where the sun rises and sets at the 
Solstices.  One should, I think, be able to read this directly off the face 
of a sundial, given the time of sunrise/sunset on the solstice.


I found a web site with a java applet that will perform that calculation, 
given your latitude, longitude, time zone, etc.  I found another that 
claimed that the answer is simply (1/cosine *  latitude) -- which did not 
agree with the result from the java applet.  I think the applet is probably 
correct.


Is there a straightforward formula that gives the azimuth of sunrise at the 
solstice as a function of one's latitude?


Jack



At 05:25 AM 12/23/2007, Peter Mayer wrote:

Hi,
   The recent discussion of Newgrange reminded me of a minor, domestic 
example

from Down Under.
   In 2002 we undertook major renovations to our 1880s stone 
cottage.  Among the

major changes (a new storey, etc.) one minor change involved shifting the
location of the east facing door.  When, 18 months later, we moved back 
into the
house, we found--to our great delight--that quite inadvertently the door 
and the
passage leading to it were nearly perfectly aligned with the Southern 
Hemisphere

solstice.  It isn't Newgrange! but the sunrise light flooding in for a brief
period in summer is an arresting experience.
This photo was taken on 20 December (taken early because the weather bureau
correctly predicted clouds and rain on the solstice).  It was taken about 15
minutes after the time of sunrise so that the Sun could clear the trees on the
horizon.

best Holiday wishes,

Peter

 --
Peter Mayer
Politics Department
The University of Adelaide, AUSTRALIA 5005
Ph: +61 8 8303 5606
Fax   : +61 8 8303 3443
e-mail: [EMAIL PROTECTED]
CRICOS Provider Number 00123M
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Re: computer program that prints out Hour Line angles

[Jack Aubert]

There are four or five programs each with its own strengths.  Personally, I 
found François Blateyron's Shadows program to be very useful because he has 
an option to print out Cartesian coordinates of the lines in tabular 
form.  Rather than using actual angle values, which are somewhat difficult 
to lay out on a wall if you are up on a tall ladder, I used the table of 
x,y coordinates of the solstice and equinox values for the lines and laid 
them out precisely onto a sheet of masonite.  I then drilled holes at 
appropriate points on the lines and hoisted the masonite, stiffened with a 
wood brace up the wall into position.  While it was suspended there, I used 
it as a template to transfer the layout holes onto the bricks with a 
masonry drill.


Jack


At 05:27 PM 7/29/2007, [EMAIL PROTECTED] wrote:

Hi Everyone,

 I am working on another vertical declining dial with large 
declination like the one shown on page 95 of Waugh's book.  I am looking 
for a computer program or spreadsheet that would give me the hour line 
angles from the sub-style and from vertical like Table 10.4 on page 95.


I thought I had a program that did that but I cannot remember. Is 
there a program that prints out those angles?


Thanks in advanced,

Ken Clark
Elizabethtown, PA



**
Get a sneak peek of the all-new AOL at 
http://discover.aol.com/memed/aolcom30tour

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RE: Plaster Wall Sundials?

[Jack Aubert]

My first thought was that it was a trompe l'oeil, but I examined the 
shadows and they seem to be cast exactly as they would at the time 
indicated by the gnomon.  On looking again, however, it does seem that some 
of the same imperfections in the background continue on through to the dial 
face.  If it is a trompe l'oeil, the photo was taken at just the right 
moment to enhance the illusion.


Jack



At 08:46 AM 5/29/2007, John Carmichael wrote:

xml:lang="en">
Dear Edley (cc Karl Schwarzinger)

Thank you for your thoughts on this, but this 3 dimensional plaster 
technique is not traditional fresco painting which is two dimensional 
painting.  David Hindle told me the name of this technique.  It is called: 
"pargeting"  see this informative article about pargeting in Wikipedia: 
http://en.wikipedia.org/wiki/Pargeting


Yesterday, after I sent my email, I looked closer at the Austrian sundial 
that I thought was pargeting.  Take a good close look at this photograph: 
http://advanceassociates.com/WallDial/Dials/PWS_208a.jpg
At first glance, this dial looks like three dimensional pargeting. But I 
now think that this sundial is an excelent tromp l'oeil made to look like 
pargeting! 
(http://en.wikipedia.org/wiki/Trompe_l'oeil 
)   Maybe it was the artist's intention to fool us.  What do you think?


I am sending this email to Karl Schwarzinger to ask him since he designed 
it.  Karl, can you tell us if this is a tromp l'oeil flat fresco dial or a 
painted 3 dimensional pargeting dial?


John C.

--
From: Edley McKnight [mailto:[EMAIL PROTECTED]
Sent: Monday, May 28, 2007 9:26 PM
To: John Carmichael
Subject: Re: Plaster Wall Sundials?

Hi John,

Surely these are Limestone Fresco.  Almost all of the buildings were made 
of Limestone.  The Fresco's were made from Lime Putty compounds.  Lime 
Putty and Lime Putty Whitewash slowly change to limestone.  Limestone is 
calcined at about 1100 degrees, then slaked in the proper amount of water. 
The slaking process for fine Lime Putty can take many years.  In the 
process the Lime is changed fully or partially to Hydrated Lime 
Putty.  This putty is mixed with finely ground limestone, washed river 
sand, crushed rock, and mineral pigments to make a plaster or a thick 
slurry or a thin paint.  After it has cured in place it slowly oxidizes to 
again become Limestone.  Again this took time to fully happen.  This kind 
of whitewash ( can be colored ) when it dries and starts to oxidize 
expands to fill cracks and forms a complete layer of firm 
limestone.  Since it is all limestone, it expands and contracts at the 
same rate throughout so that there is no flaking off or cracking.  I know 
this is all hearsay as I have no written records.  I learned this from 
working with repair artisans and families of traditional artists and from 
my dad, a Civil Engineer.  It is important not to mix these products with 
modern materials. Sacks of Hydrated Lime wont do.  Yes, Gilding is 
possible.  Before the 1930s even here in the Americas this was the way it 
was done.


I hope this helps!

Edley.






> Hello All:
>
> While researching wall sundials, I have come across a few sundials
> that seem to be made of sculpted 3 dimensional plaster that is
> attached to walls. Often the plaster looks like it's painted.
>
> I have not been able to find out anything about this type of media,
> nor am I sure if what I am seeing is plaster or something else.
>
> Does anybody know the name of this form of artwork? It must have a
> name. Can anyone confirm if this is plaster?
>
> Here are the photos of the only three sundials I have found that are
> made using this technique:
>
> PWS 208 in Rampp, Nesselwaengle, Austria:
> http://advanceassociates.com/WallDial/Dials/PWS_208a.jpg
> PWS 391 in Bahnhofstr. 37, 01968 Senftenberg, Germany:
> http://advanceassociates.com/WallDial/Dials/PWS_391a.jpg
> SCTC 29 in Kaliningrad Russia:
> http://www.advanceassociates.com/Sundials/Stained_Glass/CupolaSundial/
> Dials/SCTC_29a.jpg
>
>
> Thanks,
>
> John
>
>
> p.s. I will be in Italy from June 1 to June 20 and will only have
> sporadic email contact.
>


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RE: Programs

[Jack Aubert]

Brad,

The domain (and web site) is owned by David Bell.

Jack

At 03:00 PM 2/6/2007, you wrote:

Content-class: urn:content-classes:message
Content-Type: multipart/alternative;
boundary="_=_NextPart_001_01C74A29.6E83B240"

Bob:
it turns out the programs are still on the site and that the correct links 
are:


http://advanceassociates.com/Sundials/Lufkin-SUNDIALS-PC/ 
and

http://advanceassociates.com/Sundials/Lufkin-SUNDIALS-MAC/

I'd like to add a Java version of the program.  This will run on any 
machine with a Java Runtime Environment, down-loadable free from Sun. I'd 
like to add this to the Advance Associates site, but there's one problem: 
I don't know who set it up.

Brad


--
From: Robert Terwilliger [mailto:[EMAIL PROTECTED]
Sent: Friday, February 02, 2007 8:20 PM
To: Lufkin, Brad (Mission Systems)
Subject: RE: Programs

> Is that because the programs are no longer available through the website?

Probably. Is  there a link now?

Best,

Bob Terwilliger
NASS Webmaster




--
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] 
On Behalf Of Lufkin, Brad (Mission Systems)

Sent: Friday, February 02, 2007 4:46 PM
To: Sundial Mailing List
Subject: Programs

Someone was kind enough to host my Sundial programs for the Mac and PC on 
a website somewhere; there was also a link to the programs on the NASS 
links page. The links are now gone. Is that because the programs are no 
longer available through the website?


Brad

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