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

[rodwall1...@gmail.com]

Hi Rodger,
Thanks for the description on how to graphical design a analemmatic sundial.

It maybe me but I am having problems in following your instructions. I find it 
very hard to follow some parts like.

"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."

Does this mean onto a table with legs, or are you referring to a table flat on 
the ground, the sundial is to be on the ground? When you get down onto the 
table. Which way do you face and which way do you turn the disc to see it on 
the edge? And how do you see the edge of the disc as a straight line and where 
does the true length fit in. 

It maybe me but I am lost as to what it means. Please don't think I am being 
negative. I just want to understand how to use this method to draw analemmatic 
sundials. I think it would be a great method if I could only understand it.

I don't know if you have the time to perhaps add some drawings to also show 
each step? I think some drawings may help me to understand it better. They say 
a drawing replaces a 1,000 words.

There also maybe teachers in this group who also find it hard to follow. They 
might want to use this method in their classroom.

Thank,

Roderick Wall.

- Reply message -
From: "Michael Ossipoff" 
To: "Roger" 
Cc: "sundial list" 
Subject: Is this sundial business 'genuine', or not?
Date: Sat, Jul 21, 2018 8:09 AM

Roger--

I re-emphasize that I'm not attacking the validity of your explanation. As
I said, the sundial-construction explanations based on an orthographic
projection never made sense to me. I'm not saying that they aren't valid,
only that weren't helpful to me.

It seems to me that, when you seek to explain the Analemmatic without the
trig, then, by the time you cover everything relevant to it, without
leaving unanswered questions--then you end up with something much more
complicated and difficult than the trig explanation.

Michael Ossipoff

On Tue, Jul 17, 2018 at 7:31 PM, Roger  wrote:

> 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 

Re: Dickens' sundial

[Patrick Vyvyan]

Can't help with the current location, I'm afraid. But this link may be of
interest to some
https://www.bodleian.ox.ac.uk/johnson/jj-images/galleries/dickens

It illustrates publicity for a commemorative version of Dickins' sundial
made by Francis Barker and which copies the original commissioned by the
writer.

Best wishes, Patrick Vyvyan

On 21 July 2018 at 04:21, Ian Maddocks  wrote:

> Hello Diallists
>
>
> Whilst trawling Instagram #sundial i found this, asking for info about a
> dial once belonging to Charles Dickens.  Can anyone help them?
>
> There's a drawing and photo provided in the link below
>
> https://www.instagram.com/p/BldQFsbAixH/?tagged=sundial
>
>
> Ian Maddocks
> Chester, UK
> 53°11'50"N  2°52'41"W
>
>
>
>
> dickensmuseum The Missing
> Sun-Dial
> **
> The sun-dial stood 4ft 8in high, in the garden at Gad’s Hill (Dickens's
> final home) in a most prominent position as it was considered one of
> Dickens's most valuable treasures.
> *
> After Dickens’s death [in 1870], it was bought by Mr. Crighton, of
> Rochester. Alice Morse Earle, in her 1902 book Sundials and Roses of
> Yesterday, says that the dial was later sold in London for the sum of £50.
> An article in the Pittsburg Press, 14 February 1899, gives more details
> “There is offered for sale by a curiosity dealer in London the old sun-dial
> and stone column formerly the property of Charles Dickens.’ In 1907 it was
> exhibited in the ‘Pickwick exhibition’ in London, and had been lent by the
> company Francis Barker sundial and barometer specialists, 12 Clerkenwell
> Road, London. The company was also making replicas of the original to sell.
> *
> As we continue our search, let us know if you can shed any light on the
> mysterious whereabouts of the sundial.
>
> ---
> https://lists.uni-koeln.de/mailman/listinfo/sundial
>
>
>
---
https://lists.uni-koeln.de/mailman/listinfo/sundial

[no subject]

[John Davis via sundial]

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.--- Begin Message ---
Hi Ian,
I have been searching for the Dickens sundial for a number of years and wrote 
briefly about it in the March 2013 BSS Newsletter. The trail has gone cold 
since then though one of my contacts in the Dickens Society did send me quite a 
good B photograph which allows the inscription to be read and the profile of 
the gnomon to be seen. It came from a book. If the dial does resurface, it 
should be easy to recognise.
Regards,
John
 Dr J Davis
Flowton Dials http://www.flowton-dials.co.uk/
BSS Editor http://sundialsoc.org.uk/publications/the-bss-bulletin/


  From: Ian Maddocks 
 To: "sundial@uni-koeln.de"  
 Sent: Saturday, 21 July 2018, 9:21
 Subject: Dickens' sundial
   
 Hello Diallists
Whilst trawling Instagram #sundial i found this, asking for info about a dial 
once belonging to Charles Dickens.  Can anyone help them?There's a drawing and 
photo provided in the link 
belowhttps://www.instagram.com/p/BldQFsbAixH/?tagged=sundial
Ian MaddocksChester, UK53°11'50"N  2°52'41"W



dickensmuseumThe Missing Sun-Dial
**
The sun-dial stood 4ft 8in high, in the garden at Gad’s Hill (Dickens's final 
home) in a most prominent position as it was considered one of Dickens's most 
valuable treasures.
*
After Dickens’s death [in 1870], it was bought by Mr. Crighton, of Rochester. 
Alice Morse Earle, in her 1902 book Sundials and Roses of Yesterday, says that 
the dial was later sold in London for the sum of £50. An article in the 
Pittsburg Press, 14 February 1899, gives more details “There is offered for 
sale by a curiosity dealer in London the old sun-dial and stone column formerly 
the property of Charles Dickens.’ In 1907 it was exhibited in the ‘Pickwick 
exhibition’ in London, and had been lent by the company Francis Barker sundial 
and barometer specialists, 12 Clerkenwell Road, London. The company was also 
making replicas of the original to sell.
*
As we continue our search, let us know if you can shed any light on the 
mysterious whereabouts of the sundial.
---
https://lists.uni-koeln.de/mailman/listinfo/sundial



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

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

[Ian Maddocks]

Hi Gents


Glad to see sundial education still being well discussed, though i fear we have 
quite a way to go.

In my Instagram trawls a while back was a video of a lady standing on an 
analemmatic dial

"It's a great sundial" she said, "You stand on your birthday"



Ian Maddocks
Chester, UK
53°11'50"N  2°52'41"W














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 line are the points where you stand on the analemmatic 
sundial.



In one class activity session all the kids with a good teacher could make their 
own analemmatic sundial based on these simple concepts. It involves simple 
tools  from the standard geometry set and a simple concept of looking at a 
circular disc with a rod through the center from different points of view.



The general problem is that sundials are not on the curriculum for any school 
boards. Teachers teach to the curriculum. The few teachers I have met in NASS 
are excellent but there are very few others are interested in such an 
extracurricular activity. Perhaps that is the value of a analemmatic sundial 
installation at a school would be to stimulate interest.



Regards, Roger Bailey

Walking Shadow Designs



From: Jack Aubert
Sent: July 17, 2018 6:27 AM
To: 'Michael Ossipoff'; 'sundial 
list'
Subject: RE: Is this sundial business 'genuine', or not?



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 

Dickens' sundial

[Ian Maddocks]

Hello Diallists


Whilst trawling Instagram #sundial i found this, asking for info about a dial 
once belonging to Charles Dickens.  Can anyone help them?

There's a drawing and photo provided in the link below

https://www.instagram.com/p/BldQFsbAixH/?tagged=sundial


Ian Maddocks
Chester, UK
53°11'50"N  2°52'41"W





dickensmuseumThe Missing Sun-Dial
**
The sun-dial stood 4ft 8in high, in the garden at Gad’s Hill (Dickens's final 
home) in a most prominent position as it was considered one of Dickens's most 
valuable treasures.
*
After Dickens’s death [in 1870], it was bought by Mr. Crighton, of Rochester. 
Alice Morse Earle, in her 1902 book Sundials and Roses of Yesterday, says that 
the dial was later sold in London for the sum of £50. An article in the 
Pittsburg Press, 14 February 1899, gives more details “There is offered for 
sale by a curiosity dealer in London the old sun-dial and stone column formerly 
the property of Charles Dickens.’ In 1907 it was exhibited in the ‘Pickwick 
exhibition’ in London, and had been lent by the company Francis Barker sundial 
and barometer specialists, 12 Clerkenwell Road, London. The company was also 
making replicas of the original to sell.
*
As we continue our search, let us know if you can shed any light on the 
mysterious whereabouts of the sundial.
---
https://lists.uni-koeln.de/mailman/listinfo/sundial