Re: Is This True?

[dbell]

WHAT?!? Elvis is *dead*???


> No, It is not true. This is old news. I engaged in an interesting exchange
> of information with Alex Rawls and analyzed the tower as a gnomon for
> Islamic prayers, The whole data does not support the thesis. The Asr
> prayer line curves the other way. You have to invoke several complexities
> to achieve any kind of fit. I am satisfied that this is conspiracy theory,
> based on coincidence and a selective review of the data to support the
> premise. Add complexities when the facts deviate from the premise as in
> any classical conspiracy theory.
>
> I think this was discussed on the SML previously. I think I quoted Occam's
> Razor that the simplest explanation is likely correct. "When competing
> hypotheses are equal in other respects, the principle recommends selection
> of the hypothesis that introduces the fewest assumptions and postulates
> the fewest entities while still sufficiently answering the question."
>
> That said, the architect showed arrogant insensitivity in choosing a red
> crescent as the dominant theme for his circle of red maple trees. Yes, the
> opening in the crescent does sort of point to Mecca. He says these are
> accidents of the geography of the crash site. Yes, the choice of a tower
> as the other highlight for the memorial is unfortunate as towers are used
> by Moslems as minarets for their call to prayer but also by Christians as
> bell towers. "For Whom the Bell Tolls" is a classic memorial. I give my
> heartfelt thanks to the rugby team members that said "Let's roll", fought
> back and brought down the plane before its intended Washington target.
>
> It is unfortunate that the memorial site is diminished by this
> controversy, The architect was insensitive not considering the symbolism
> of the red crescent and a tower  and the opponents are highly sensitive,
> over-interpreting the evidence.
>
> Remember that almost a majority of Americans believe the moon landings
> were fake, that Kennedy was killed by the Russians or a right wing cabal,
> that the twin towers were destroyed by Mossad and the CIA and Elvis lives.
>  I remain a skeptical non-believer of these and other widely held beliefs.
>
> Regards Roger Bailey
>
>
> From: Richard Mallett
> Sent: Thursday, October 14, 2010 12:42 PM
> To: John Carmichael
> Cc: 'Sundial Mailing List'
> Subject: Re: Is This True?
>
>
> On 14/10/2010 17:17, John Carmichael wrote:
>   Yesterday, I received an email from a fellow dialist containing the
> following link to an article written by some group called The Canada
> Free Press.  He wanted to know if I could confirm its veracity.  I've
> heard nothing about it.  Have you?
>
>
>
>   In the article it says this, among other things, about the Flight 93
> Memorial presently being built in Shanksville Pennsylvania at the crash
> site:
>
>
>
>   "Another feature of paramount significance is a colossal 93-foot
> minaret-like tower that Rawls argues indicates time for prayer by
> functioning as an Islamic sundial."
>
>
>
>   Do any of you know if anything in this article is true?
>
>
>
>   See:
>
>
>
>   http://canadafreepress.com/index.php/article/28649
>
>
>
>
>
>
>
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
> This has been going round the Internet for months (years ?) - see a
> balanced account at :-
>
> http://en.wikipedia.org/wiki/Flight_93_National_Memorial
>
>
> --
> --
> Richard Mallett
> Eaton Bray, Dunstable
> South Beds. UK
>
> 
>
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>



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Re: DST Misconceptions

[dbell]

> Even in Kunming, a much more culturally Chinese area, people liked to
> quote the time-honored maxim that "the mountains are tall and the emperor
> is far away."

I had to think of the line from Fiddler:

"Is there a proper blessing for the Czar?"
"Yes, 'May God bless and keep the Czar --- far away from here!'"

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Re: how Italian hours

[dbell]

Roger Bailey wrote:

> The conversion of the
> presentation to an article fro the compendium is stalled at 80% complete.
> This follows the classic 80 20 rule defining work progress.

Which is to say that the remaining 20% of work will consume the *other*
80% of time?

Dave


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Re: New type of clock

[dbell]

> All,
>
> A friend of mine (Joe Rao of New York City) just sent me this neat link.
> Check it out!
>
> -- Roger
>
> A different way to display time on the green time line.
>
> This is a real cool clock! I  believe it comes from a Dutch web site.

Yes!  Some really cool things you can program in Flash...

Did you try clicking on the "sliderule" clock?
That brings you to a page full of interesting clock programs.

Dave

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Re: Marton Géza's 2010 calendar

[dbell]

> I have uploaded Marton Géza's magnificent sundial calendar to:
> http://www.twigsdigs.com/2010/calendar_2010.pdf


Thank you, Bob!

Merry Christmas

Dave

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Re: Troublesome things these sundials!

[dbell]

>The poor image attached might just
> be small enough to get transmitted but it certainly shows the extensive
> damage.

Wow, looks like most STOP signs in the southern US, peppered with bullet
holes... Some kinds of stupidity are universal, I guess.

Dave

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RE: BSS web site

[dbell]

The space-holder site seems to be safe, for what that's worth.
I think Fabio hit it on the head, with the domain registration expiring.
Looks like it was successfully re-registered, so once the DNS information
is passed through the system, it should return to accessability.
Unfortunately, the IP address in the WhoIs record ( 69.64.155.127 ) is
still dead, leading to "searchalligator", another fall-back page.

Dave

> I tested the link http://www.sundialsoc.org.uk/ on both Mozilla Firefox
and
> Internet Explorer after deleting the browsing history caches of both,
and
> that stupid lawn website keeps coming up.  Note that on that website,
there
> is no way to contact the owners or the webmaster of that site!
>
> Note to Dave Bell: Hey Dave, since you know more about webmastering than
most of us, could you look at this bogus website and see if there is
anything odd about it (a virus maybe?).  Could somebody have hijacked the
> BSS site?  Who holds the domain name registration?
>
>
>
>
> -Original Message-
> From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de]
On
> Behalf Of Andrew James
> Sent: Wednesday, November 25, 2009 3:56 AM
> To: sund...@rrz.uni-koeln.de
> Subject: BSS web site
>
> Dear all
>
> I thought the British Sundial Society web site was at
> http://www.sundialsoc.org.uk/ - but it seems to have been hijacked to
sell lawnmowers and such like!
>
> What is going on?
>
> Andrew James
>
>
> PRI Limited,
> PRI House, Moorside Road
> Winchester, Hampshire
> SO23 7RX United Kingdom
> Tel:  +44 (0) 1962 840048
> Fax: +44 (0) 1962 841046
> www.pri.co.uk
> PRI Limited is a company registered in England and Wales with company
number
> 2199653
>Measure - Inform - Empower
>
> This correspondence is confidential and is solely for the intended
recipient(s).If you are not the intended recipient, you must not use,
disclose, copy, distribute or retain this message or any part of it. If
you
> are not the intended recipient please delete this correspondence from
your
> system and notify the sender immediately.
>
> This message has been scanned for viruses by MailControl.
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>









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Re: Location aerial photography online

[dbell]

> If I can't get a good result because the location is a new home in a new
> development, I go to bing.com and check it on their maps/aerials. They
> seem to have more recent aerial imagery much of the time.
> Jim Tallman

Unrelated to dialing, but whereas I usually prefer Google maps and aerial
and street views for general mapping needs, I *love* Bing for housing. A
coworker is shopping for her first home, and we grizzled veterans have
been kibitzing for her. Where Bing totally excels is their Bird's Eye
view. The ability to swing around a location, viewing it from four
cardinal directions and something like 30 degree elevation is fantastic!
I'd love to know more about their software and image correcting process...

Dave

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Re: Fwd: Direct reading time.

[dbell]

Use the best clock of all, the Sun (or Earth, if you prefer that new
notion  of Copernicus') - a photocell to track the Sun, advancing the
mechanism one tick per day.

Dave

> Bill
>
> All we need now is a good clock to control the mechanism which compensates
> for the EoT?
>
> Brian Albinson
>   - Original Message -
>   From: Bill Gottesman
>   To: Robert Bargalló
>   Cc: sundial@uni-koeln.de
>   Sent: Sunday, September 27, 2009 10:24 AM
>   Subject: Re: Fwd: Direct reading time.
>
>
>   I like it.  I would like to hear the story of how it was designed and
> fabricated.  Is it located at a residence or a public place?
>
>   -Bill Gottesman
>   Burlington, VT
>
>   Robert Bargalló wrote:
>
>
>
> -- Forwarded message --
> From: Robert Bargalló 
> Date: 2009/9/17
> Subject: Direct reading time.
> To: Robert Bargalló 
>
>
>
> Hello All,
> When an inexperienced person examine a well constructed Sundial, often
> underestimate the instrument because it is not marking the official
> time and having to make some “antipathetic” corrections of the
> indicated time. That is the main reason we have built a sundial that
> gives civil time accurately, enough to adjust the minute a non solar
> clock that it has stopped. In a word, in our quadrant needless resort
> to the equation of time or to the local position versus the Meridian
> corresponding to the time zone. No arithmetic corrections are needed.
> Descriptively, the device is a horizontal sundial with a gnomon
> consisting in thin thread nylon. The mechanism presents a 48 teeth
> gear, powered by an endless screw, which allows the entire clock to
> rotate some degrees around an axis parallel to the Earth rotation axis
> (around the gnomon). In other words, the mobile set plays like a
> hypothetical sundial indicating the exact civil time is elsewhere, in
> another position but in the same geographic parallel. As to the
> accuracy, the quadrant presents marks of all the minutes from the 5 h
> 45 a.m. until the 8 h 15 p.m. The single need featuring the device is
> that one or twice a week requires adjusts a rotatable knob to indicate
> the current date. This disc, of course, acts on the endless screw and,
> for that reason, on the rotation.
>
> Really, the rotation movement compensates not only the equation of the
> time, but also the error caused for the geographic longitude position
> of the instrument.
>
> For the same method we can use the sundial giving 3 types of time: the
> local solar time, the standard time, or the daylight savings.
>
> Since we installed it, from November 2006 to date, it has indicated
> time with an error that in no case exceeded one minute.
> Happy Dialling!
>
>
> Robert Bargalló
> More information at next blog
>
>
> 
> ---
> 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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[Fwd: RE: gnomon protection - shadow ridge dials]

[dbell]

Larry, I agree that waiting an hour (or 15 minutes, even) between brief
illuminations would make it less usable. A couple of suggestions:

A bunch of fiber strands spread across the bottom of each (larger
diameter) well, converging into a single lighted spot. The brightest spot
indicates the closest hour (or other interval), and an estimate can be
made from the next-brightest.

A graded filter, clear in the center, covering each well, with a single
fiber in the center of the base. Works similarly to the above.

Dave

> Rodney,
>
> Great illustration of what I call an incremental time dial (i.e., it only
> tells time at set increments throughout the day).
>
> About 20 years ago I had a dream of just such a hollow, thick skinned
> sphere
> (actually two spheres - one for each solstice to solstice period), but
> drilled with holes pointing to the sun's position (split analemmic
> pattern,
> one hole for each hour on the first, tenth, twentieth, thirtieth days of
> the
> month.
>
> Now envision each hole as a "well" and have fiber optic strand recessed
> inside the well such that the end of the strand is illuminated for just a
> short period that the sun is directly in line with the axis of the well.
> The fiber can be run to a display readout indexed for the date and time by
> which fiber is illuminated.
>
> While all of this might be technically possible, it strikes me that this a
> would be very expensive dial to make as well as being disappointing to
> users
> in having to wait for the sun to hit one of the wells in order to tell the
> time. The only solution to the latter is to create more holes and fiber
> strands and adding further to the cost of construction.
>
> I leave the idea to anyone who wants to pursue it.
>
> Larry Bohlayer
>
>
>
> -Original Message-
> From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de]
> On
> Behalf Of David Bell
> Sent: Sunday, September 06, 2009 2:42 PM
> To: Rodney Heil
> Cc: sundial@uni-koeln.de
> Subject: Re: gnomon protection - shadow ridge dials
>
> Very nice! I was thinking of it on a flat surface, with the tubes
> variously inclined, but this spherical model works great, too. Call it
> a Sea Urchin dial, maybe...
>
> Dave
>
> Sent from my iPhone
>
> On Sep 6, 2009, at 11:36 AM, Rodney Heil  wrote:
>
>> I made a quick POV-ray model of my conception of an "anemone dial" or
>> "porcupine dial" and it is posted at
>> www.flickr.com/photos/sundialstuff.  Thanks to Roger for suggesting
>> flickr.
>>
>> Respectfully,
>>
>> Rod
>> ~35.5 N 117.5 W
>> ---
>> https://lists.uni-koeln.de/mailman/listinfo/sundial
>>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>



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Re: Inclining Cone Gnomons

[dbell]

Obviously, your insurers are well familiar with US litigiousness (and
perhaps, incompetence!)

Dave

> My insurers wanted $2,000,000 indemnity to cover the possibility of US
> clients falling onto a dial gnomon. They actually suggested building a
> wall around the dial to keep everyone at a safe distance! I solved the
> problem (to my satisfaction) by always having a 'halfpenny scroll tip'
> on my gnomons thereafter.



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Re: Electrical sundial tested

[dbell]

Excellent project, Aimo! I look forward to seeing this evolve.

Dave

> As some of you already may have noticed, I have recently worked with my
> electrical sun dial project. Instead of a shadow  the sun's position is in
> it calculated from the output of two or more solar panels. I have now
> tested
> the first prototype and found it capable for surprisingly accurate
> results,
> +-40 sec or even better, if the conditions are good. A description of the
> project is available at
> http://pc-calculator.110mb.com/sun/digital-sundial.html
>  It has been really amazing to see how tiny  movements of the sun the
> instrument capable to observe.
>
> Aimo Niemi
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>


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Re: Help with 'Analemmatic' - thanks to all, especially John Davis

[dbell]

> It was interesting to see responses change, as time went on - from
> initially saying that it was simply not possible, to some 'lateral
> thinking' which could actually fulfill the design envisaged by our
> Mr Phillips

Alison, that's the beauty of a group like this one, and something I've
recognized many, many times, from the "engineering mentality." All it
takes is for someone (even one's self) to state that a task is impossible,
to start the processes working to come up with creative solutions!

Best of luck with Mr. Phillips. With John's help, I'm sure you can all
come to an agreeable solution.

Please let us know how it resolves, and send us photos of the dial!

Dave Bell
California

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RE: Advice wanted, on 'Analemmatic' sundial orientation

[dbell]

Andrew James wrote:

> If, instead of standing on the central "month" scale, the user finds and
> stands on or near the hour number which casts his shadow onto the
> appropriate date, the numbers might be arranged to the South rather than
> to the North of the centre. This requires more action on the part of the
> user.

Best practical suggestion I've seen yet!
It would require making the date line markers visible from a distance, or
possibly a daily (or weekly) placing of a small pylon by facility
personnel.

> If the hours were not in a horizontal plane, perhaps they could be
> arranged to lie on a semicircle in some other plane - though not, I
> think, what Mr Phillips would like?

Considering the relatively (to central US) high latitude, it might not be
too extreme. Something like a ramped walkway (semi)encircling the area of
the dial face.

Dave


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Re: Advice wanted, on 'Analemmatic' sundial orientation

[dbell]

Good luck, Alison!
I'll let the real experts address the weight of evidence, but you are
quite correct, and Mr. Phillips is wrong. While many types of sundials can
indeed be "adjusted" to operate in any location, they cannot be adjusted
to arbitrary orientation.
For the simplest argument you might present to him, point out that the
human gnomon casts a shadow to the North (at say, local noon). It would be
impossible to place the hour lines/points to the South and have them
function! (He isn't from Australia, by any chance?)

Dave

>
> Dear Sundial Experts,
>
> I have recently joined this Mailing List, and hope that any members
> will be able to give me some assistance on the following situation.
>
> Our local Stately Home ("Kentwell Hall", Long Melford, Suffolk) is
> considering installing an Analemmatic sundial, as a new interactive
> attraction for visitors - but we are getting 'conflicting' advice,
> on whether this 'Human Sundial' will work in the way we want it to.
>
>
> We have been in discussion with "Modern Sunclocks" (apparently the
> acknowledged 'experts' for these features), who have told us that
> its central scale of dates must be aligned North/South - plus that
> hour markers must be correctly positioned on an elliptical ring,
> and which would lie on the Northern side of that scale of dates.
>
> Photographs on their website ( www.sunclocks.com ) confirm this.
>
>
> However, our 'Director of Operations' (Mr Phillips) absolutely
> INSISTS that he wants the scale to run exactly parallel with our
> main driveway - on a compass bearing which is about 162 degrees
> from North, with the hour points placed on its Southern side.
>
> He also wants the hour points to form an exact semi-circle, and
> not be elliptical in shape.  Mr Phillips refuses to accept that
> he cannot arbitrarily position the Human Sundial feature as he
> wishes, and says that it must be possible to create this so that
> it could then align with the existing layout of buildings/paths.
>
>
> Can anyone on this Mailing List tell me whether it is possible to
> install a Human Sundial to fit any existing orientations, (with
> appropriate re-calculation of its component parts) - or, if not,
> just confirm that it must be as "Modern Sunclocks" have told me.
>
> I can then show the 'weight of evidence' to Mr Phillips.  Because
> "Kentwell Hall" is a well-known Stately Home (open to the public),
> we should not want to become a 'laughing stock' by installing a
> feature which does not work - despite Mr Phillips assurance that
> "all types of sundial can be adjusted to work, in any location".
>
>
> Looking forward to all comments (to this List, or sent privately).
>
>
> Sincerely,
>
> Alison Shields.
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>


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Re: A Most Beautiful Dial!

[dbell]

Also curious, I don't recall any mention of the two auxiliary dials, with
the cherubim holding their own styles, one 4 hours "fast", the other 4
hours "slow" relative to the main dial. And what about the apparent four
additional styles, one at each lower corner of the window frames?

Dave

> Dear John,
>
> Thank you for bringing this to our attention!
> The Wilanow Palace sundial photo and its description can also be found
at: http://en.wikipedia.org/wiki/Image:Warsaw_Wilanow_Palace_sundial.jpg
This is indeed an interesting sundial, but also an interesting photo.
>
> Karl Schwarzingers photo led him to state that "Chronos holds style with
a pierced gnomon shaped as sun", and indeed it looks that way in his
photo. The hi-res one clearly shows that the supposed pierced gnomon
actually is a sun face stuck to the wall. So the date is read at the tip
of the rod, which fits in with the date the photo was taken: June 25.
>
> In addition, the rod is not a pole style, which is clear from the fact
that its shadow does not line up with the hour lines.
>
> Best regards,
> Frans
>
> John Carmichael wrote:
>> Recently I came across a website that has a high definition photo of
what I think is one of the world’s most beautiful sundials.   It is a
sundial made of sculpted painted plaster or stone (I can’t tell which),
and it’s located on a wall of The Royal Palace of Wilanow  in Warsaw
Poland.  (Actually, it’s a multiple dial with three separate faces).  I
have known about this dial for years now from Karl Schwartzinger’s
website.  But Karl’s photo was not of high quality and I never was able
to find a high resolution photo of it until now.  If you have a slow
modem, It’s worth the wait to see it in high definition.
>> High Definition Photo (2 MBs) :
>> http://upload.wikimedia.org/wikipedia/commons/b/b1/Warsaw_Wilanow_Palace_sundial.jpg
You must also see the closeup photos of it at this website (click on
the
>> word “dalej>” under the photo):
>> http://www.wilanow-palac.art.pl/index.php?id=195
>> Here are the other photos of it on Karl’s site:
>> http://members.aon.at/sundials/bild33_e.htm
>> Enjoy!
>> John Carmichael* *
>> *Dial 31*
>> *Delineator: *John Hevelius, astronomer of Gdansk and Adam Adamandy
Kochanski, royal librarian and mathematicians
>> *Painter: *unknown
>> *Location: *Poland, Warsaw, The Royal Palace of Wilanow
>> *Date: *1681-1682, Restored 1995
>> *Photo Origin: *Photo ‘a’ was taken by Arnold Paul on 06-25-2006 and is
copied from Wikimedia.org website below. Photo ‘b’ is by Karl
>> Schwarzinger and was sent to us by him.
>> *Photo Permission: *Photo ‘a’ is used following terms of the license
below. Photo ‘b’ is used with permission from Karl Schwarzinger. Please
do not copy photo ‘a’ without using the license available online.
Please
>> do not copy photo ‘b’ without permission from Karl Schwarzinger. *Karl
Schwartzinger’s Website:
>> *http://members.aon.at/sundials/bild33_e.htm
>> *Website: *http://www.wilanow-palac.art.pl/index.php?id=195
>> *Website:
>> *http://commons.wikimedia.org/wiki/Image:Warsaw_Wilanow_Palace_sundial.jpg
*Creative Commons License:
>> *http://creativecommons.org/licenses/by-sa/2.5/
>> http://advanceassociates.com/WallDial/Pinkies/PWS_031a.jpg
>> http://advanceassociates.com/WallDial/Pinkies/PWS_031b.jpg





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Re: Astronomical Clocks

[dbell]

I just ran across this photoset today.
Along the same lines as the Prague clock, and reminds me of Jim's
beautiful astrolabes...

http://www.flickr.com/photos/seangallagher/sets/72157604323095889/detail/

or

http://tinyurl.com/5fjs3q

Dave

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Re: Dali sundial +

[dbell]

> Some time ago someone posted a link to a painting by Salvador Dali that
> included a sundial.
>
> Could someone point me to it again?

I found this:
http://peregrinations.kenyon.edu/vol1-3/gower.pdf


> == Try this: ==
>
> Since it has none, I suppose a sundial could be considered the timepiece
> with the least moving parts.
>
> What timepiece has the most moving parts?

Why, an hour glass, of course!

Dave

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Re: Monumental sundial

[dbell]

> As you
> probably know, Britain (and England in particular) is filled with such
> memories of the past and we tend to take them for granted until others
> mention them!.

I find the same here, except our "past" is so recent, compared to yours!

Dave

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Re: Monumental Sundial

[dbell]

Very intriguing idea, Edley!
Should be great fun experimenting.
I'm going to look for some trial ray-tracing software...

Dave

> Some time ago an idea for a nodus on a Large Sundial appeared to me.
> It is the shadow of a thin-walled transparent sphere.  This can be seen
> simply in the shadows of soap bubbles and transparent round helium
> balloons.  This is not considering it a lens, just the shadow cast.  As a
> lens, such a structure is a diverging lens, but the shadow has a bright
> spot
> when the distance is proper for it's size.  The central light bundle is
> little
> refracted and outer bundles are reflected at Brewster's or other angles,
> leaving a
> surrounding shadow.  It appears much like the shadow of a disk with a hole
> in it, but works the same with light from all directions.  At a proper,
> and quite large distance, the central aperture acts much like a pinhole.
> I've not tried large spheres, but possibly those of glass or plastic,
> especially coloured transparent materials would give a distinctive small
> bright spot
> surrounded by shadow.
> I've no idea how to calculate the proper dimensions, size, wall thickness,
> surface shinyness, etc.  But, it could work very well at hundreds of feet
> away.
> If someone figures out how to calculate this effect, I'd be pleased to
> hear about it.
>
> Thanks!
>
> Edley McKnight
>
> PS. John, I decided to let the list know.
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>


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Re: Dialist for PDA

[dbell]

Simon wrote:
> Of course, if you had C, C++, FORTRAN, LISP, COBOL,
> JAVA, Python, Scilab, Euler, Pascal, Basic, etc on
> your PDA, then you might look at my web site. I added
> the Python, Scilab, and Euler code for dial design
> just this week.

What?!? No SNOBOL?

On the other hand, Forth would actually be very reasonable for a small
platform like a PDA. Of course nowadays, you'd have to implement the
kernel in Java!

Dave

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Cute ad-hoc dial at AutoDesk Labs

[dbell]

"World's cheapest sundial":



Dave

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Re: bone terrestrial globe with sundial

[dbell]

> I happen to own a small version of this exact item.  I must concur with
> Sara that it is not what it purports to be.  I picked up the small (about
> 5" high) version a few years ago as a curiosity - lamenting all the time
> that the gnomon design and placement make the whole thing useless.  This
> is almost definitely a modern attempt (made in several different sizes!)
> to put one over on emptores who ignore the caveat!
>
> Fred Sawyer

Especially from Fred's experience with seeing similar dials, I agree with
its lack of authenticity. My only thought about the gnomon design on first
seeing the eBay photos was that the globe/dial might be designed with a
tilted or even adjustable polar angle, like most modern globes. Wouldn't
that make the dial a polar design, and the perpendicular style edge
correct?

Dave
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Old dial design article

[dbell]

Interesting article from a 1949 Mechanix Illustrated...

http://tinyurl.com/37ff9x

Dave
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Re: Direct South Dial

[dbell]

While Willy is absolutely correct, the part about knowing and computing
for the shape of the dish is probably the real killer task.

This is an application where I would advocate the empirical approach:
Properly orient the dial face and style, then manually lay out points,
with a watch in hand. Plan ahead and (weather cooperating) do it on the
Equinox, and you can draw lines through the points to the dial center, at
the root of the style.

Dave

> Hi Andrew,
>
> you have to orient the disc to the south
> you have to decline the disc to a vertical position
> on a vertical and south oriented plane behind the disc you have to
> work out (virtually) the hour lines and date lines of a vertical
> south oriented nodal sundial - the node must be a part of the style
> of your sundial
> the lines from the node to 'specified points' of the plane sundial
> intersects the disc at the equivalent points on the disc ('specidied
> points' are the intersection points of the hour lines and date lines)
> to do this mathematically the shape of the disc must be known; is it
> a globe, a paraboloid, a hyperboloid ...?
>
> Willy Leenders
> Hasselt in Flanders (Belgium)
>
>
>
>
> Op 21-jun-07, om 19:27 heeft Andrew Corl het volgende geschreven:
>
>> Greetings all,
>>
>> Several months ago I bought a house and the previous owners left me
>> with one of those 12" diameter satellite dishes.  I have no need or
>> want of Direct TV or satellite TV.
>>
>> I was sitting there thinking one day that it would make a really
>> nice direct south facing sundial.  My house already faces a little
>> east of south anyway, and the location where the dish is gets
>> direct sunlight almost all year round.
>>
>> My questions is this:  Do I need to make any adjustment in the
>> calculations of the hour lines for the shape of the dish?  If so
>> what is the formula?
>>
>> I am going to install a simple style using a metal road about a
>> half inch in diameter.  I want this sundial to tell solar time not
>> necessarily actual time.  Though one day I may install an equation
>> of time underneat the dial .
>>
>> Boardwalk for $500? In 2007? Ha!
>> Play Monopoly Here and Now (it's updated for today's economy) at
>> Yahoo! Games.
>> ---
>> https://lists.uni-koeln.de/mailman/listinfo/sundial
>>
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>


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Re: An unusual Polyhedron

[dbell]

Thanks for the link to the photo, Roger.

What struck me about the dial was the disparity between the precise, very
modern looking gnomons, and the almost crude shaping and smoothing of the
stone body. Artistically, I think the contrast is elegant, and the
delineation appears to have been carefully done to match the actual
surfaces...

Dave

> If others are interested in what the Cambridge Polyhedron dial looks like,
> I
> have posted my picture of it at www.walkingshadow.info. Click on Images
> and
> then CamPoly.jpg. The picture is compressed for the web, only about 103
> kb.
>
> I suppose the sundial is multifaceted to reflect Cambridge grads. But the
> sundial is also a bit odd, misshapen with some rough edges and sharp
> projections. If you look closely, you can see the camel in the eye of the
> top gnomon.
>
> Roger Bailey
> Walking Shadow Designs
> N 48.6 W 123.4
>
> - Original Message -
> From: "Frank King" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Cc: <[EMAIL PROTECTED]>
> Sent: Thursday, June 14, 2007 12:44 AM
> Subject: An unusual Polyhedron
>
>
>> Dear John
>>   CAMBRIDGE POLYHEDRAL DIAL
>>
>> I have just received the June BSS Bulletin...
>>
>> You are to be congratulated on the cover photograph.
>> Somehow, you have contrived to make what I regard as
>> one of the most unprepossessing dials in Britain seem
>> almost elegant!
>>
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>


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RE: Equation of Time

[dbell]

> Concerning equatorial tables, people seem to be looking at recent patents
> for ELABORATE designs (conical rollers and such).  But the original Poncet
> table is quite simple. I made my 1977 prototype out of wood, with a piece
> of Formica for the inclined plane on which one end of the table slides.
> My unit has no curved surfaces at all.

I agree - all I see lately are roller bearing designs, not the sliding
plane. Smooth, frictionless motion is NOT needed here!

> I took it to Turkey for the 1999
> eclipse (latitude 39 N)

We went to Romania for 1999... Did you get out before the quake?

Dave

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Re: Russell Porter sundial

[dbell]

> The Patent for Porter's reflecting telescope is available directly from
> the patent office's online
> site at a huge long url, which is too long to type in or put on a single
> line.

For future reference, there's an easy fix for that problem:
Once you have navigated to the site with the long URL, copy it from the
address bar, then go to 
Enter the long url, hit "Make a shorter URL", and copy the tiny result to
paste into your email. They keep just the link association you create, but
keep it forever. And it's totally free...

> You can just go to:
> http://patft.uspto.gov/netahtml/PTO/search-bool.html
> and search for telescope in title and porter in inventor, yielding two
> patents, one for the
> refracting, and one for the reflecting one.(having set the full database
> period in the selection )

Another very useful free site is 
Enter the patent number, and they will retrieve the TIFF images and create
a multi-page pdf file you can download or view immediately. No TIFF plugin
required!

Dave


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Re: Analemmatic dial

[dbell]

Malcolm McClure responded to M. Jacquelin Hardy's questions
about building an anlemmatic dial:

>I am still thinking about this one, but hope the following suggestions will
>help. (Corrections to logic gratefully received)
> I have seen a photo of a wall mounted analemmatic sundial at Greenwich. It
>has a fixed perpendicular rod about a meter long at the top, with a
>sun-shaped cutout piece of metal welded on the end. This disc has a central
>hole about a centimeter in diameter, which acts as the style.
>The analemma is painted on the south-facing wall beneath, such that the top


The logic is fine, as far as I could tell, Malcolm, but I think
you're describing a different type of dial. The vertical dial
you outlined seems to be equivalent to a "conventional" dial,
with the hour lines drawn as analemmas (..ae?), to correct for
declination and EoTime. 

The one Hardy is asking about is quite unconventional, compared
to a horizontal dial, or it's vertical cousins. This type of
dial, if you look down on it from above, is layed out as roughly
half of an ellipse, with the major axis running East-West, and the
half-minor axis pointing North (in the N hemisphere!). The gnomon
is not parallel to the Earth's axis, but is a vertical pole placed
on the N-S center line, and moved N and S a small amount each day.
The "pointer" is the shadow of the top of the gnomon, and falls
on the elliptical perimeter to mark the hours. In large garden
or monumental versions, the gnomon is often designed to be the
user, who stands on date markers.

I don't have any references here at work, but I believe Waugh
did a good workup on this design. I'll see what I can find,
this evening.

Dave
[EMAIL PROTECTED]

>[EMAIL PROTECTED] (M. Jacquelin Hardy) wrote
>I am looking for info. on how to build an analemmatic  sundial ( we call them
>"cadran analemmatique" in french). There are a few of these in Europe,
>(near the church of Brou in Bourg-en-Bresse, France) is one of them.
>
>The dial is horizontal and the gnomon is vertical and moved along the
>North-South axis during the year. This movement is my problem: I read in a
>book
>that d( movement of the gnomon) is equal to tg (Decl. of sun)/cos (lat.)
>
>For example, on June 21st in lat. 45N , the gnomom should be moved
>tg 23.45/cos 45 , ie. approx. .42/.7 or .6 times diam./2 along then N-S axis
>to give the time correctly. It doesn't seem to work right according to my
>calculations.
>
>Please help!