Great post. Thanks to all.
Please, please keep it up.
From Bill O'Neill, Holland, PA. USA
-----Original Message-----
From: [email protected]
Sent: Friday, October 31, 2014 2:00 PM
To: [email protected]
Subject: sundial Digest, Vol 106, Issue 6
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Today's Topics:
1. Pumpkin geometry (Frederick Jaggi)
2. Old sundial manuscript for sale. (David)
3. Dipleidoscope on Ebay (Tom Kreyche)
4. Re: Dipleidoscope on Ebay ([email protected])
5. 1636 Samuel Foster - Sundial Manuscript with Many Drawings
(Robert Terwilliger)
6. Re: Dipleidoscope on Ebay (Larry McDavid)
7. Re: Dipleidoscope on Ebay (Larry McDavid)
----------------------------------------------------------------------
Message: 1
Date: Fri, 31 Oct 2014 08:41:50 -0400
From: Frederick Jaggi <[email protected]>
To: Sundial Sundial List <[email protected]>
Subject: Pumpkin geometry
Message-ID: <[email protected]>
Content-Type: text/plain; charset="us-ascii"
Hi Everyone:
A friend sent me this note last night:
interesting demonstration of stereographic projection:
Pumpkin geometry: stunning shadow sculptures that illuminate an ancient
mathematical technique
http://flip.it/c4yJS
Fred Jaggi
Frederick Jaggi
Horas Non Numero Nisi Serenas
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Message: 2
Date: Fri, 31 Oct 2014 12:58:08 +0000
From: David <[email protected]>
To: sundial <[email protected]>
Subject: Old sundial manuscript for sale.
Message-ID: <[email protected]>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Fellow shadow-watchers....
I understand that there is an auction of books at the Chelsea Book Fair
in Chelsea, London, UK, on November 7th and 8th amongst which is an
original early sundial manuscript by Samuel Foster 1636.The information
came to me second hand, so I don't have the full details, but the latest
edition of Clocks magazine highlights it.
http://www.clocksmagazine.com/images/clocks-look-inside.pdf
Scroll down to p.9.
David Brown
Somerton, Somerset, UK
------------------------------
Message: 3
Date: Fri, 31 Oct 2014 09:07:47 -0700 (PDT)
From: Tom Kreyche <[email protected]>
To: sundial <[email protected]>
Subject: Dipleidoscope on Ebay
Message-ID: <[email protected]>
Content-Type: text/plain; charset=utf-8
I noticed that a Dipleidoscope is up for live auction on Ebay (USA) - this
seems to be a rare offering (not in my budget!).
http://www.ebay.com/itm/DIPLEIDOSCOPE-/231365300840?ssPageName=ADME:SS:SS:US:3160
LOT 1130
Seller's Estimate: USD 600.0 - 800.0
DIPLEIDOSCOPE - England, 19th century, brass and bronze. Brass and glass
prism mechanism inset into a shaped bronze case with scrolled sides.
Engraved "Dent's Patent Meridian Instrument" and "67 Strand, London". 3"h.
2.25"w. 3"d.
------------------------------
Message: 4
Date: Fri, 31 Oct 2014 09:44:48 -0700
From: "[email protected]" <[email protected]>
Cc: sundial <[email protected]>
Subject: Re: Dipleidoscope on Ebay
Message-ID: <[email protected]>
Content-Type: text/plain; charset=us-ascii
A copy of Dent's booklet on the use and design of the Dipleidoscope is
available on line from Google Books at:
http://books.google.com/books?id=9QlbAAAAQAAJ&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false
Dave
Sent from my iPad
On Oct 31, 2014, at 9:07 AM, Tom Kreyche <[email protected]> wrote:
I noticed that a Dipleidoscope is up for live auction on Ebay (USA) - this
seems to be a rare offering (not in my budget!).
http://www.ebay.com/itm/DIPLEIDOSCOPE-/231365300840?ssPageName=ADME:SS:SS:US:3160
LOT 1130
Seller's Estimate: USD 600.0 - 800.0
DIPLEIDOSCOPE - England, 19th century, brass and bronze. Brass and glass
prism mechanism inset into a shaped bronze case with scrolled sides.
Engraved "Dent's Patent Meridian Instrument" and "67 Strand, London". 3"h.
2.25"w. 3"d.
---------------------------------------------------
https://lists.uni-koeln.de/mailman/listinfo/sundial
------------------------------
Message: 5
Date: Fri, 31 Oct 2014 12:55:55 -0400
From: "Robert Terwilliger" <[email protected]>
To: <[email protected]>
Subject: 1636 Samuel Foster - Sundial Manuscript with Many Drawings
Message-ID: <9BA186888CAF4E73BA6449176527570A@GENERAL>
Content-Type: text/plain; charset="iso-8859-1"
You can own it now - only ?4,500
Voyager
<http://www.chelseabookfair.com/antiquarian-books/d/rare-early-work-sundial-
manuscript-with-many-drawings/88127> Press Rare Books
Bob
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Message: 6
Date: Fri, 31 Oct 2014 10:15:38 -0700
From: Larry McDavid <[email protected]>
To: sundial <[email protected]>
Subject: Re: Dipleidoscope on Ebay
Message-ID: <[email protected]>
Content-Type: text/plain; charset=windows-1252; format=flowed
Well, it is an authentic 19th century antique dating from about 1845.
Note the buyer's premium also.
I have several Dent Dipleidoscopes, including a rare Dent Universal
model. I gave a presentation on the Dent Dipleidoscope at the Harvard
conference of NASS in 2013. If anyone is interested, I can provide a pdf
of that presentation. The presentation includes history, detailed
explanation of operation and lots of pictures of the construction.
The Dent dipleidoscope provided an easy and inexpensive way to set
clocks at solar noon to an accuracy of better than tens of seconds, with
an achievable accuracy of about three seconds. Short of a noon transit
instrument at an observatory, it was the most accurate way to establish
time. Arguably, a hand-carried mechanical chronometer set that morning
at the Greenwich Observatory was also popular among bankers and
watchmakers in London, though it was a relatively expensive service.
But, the Dent Dipleidoscope could be used throughout England (and,
elsewhere) even on country estates. As the British trains began to run
with minute scheduling, accurate time became much more important!
Best of all, the Dent Dipleidoscope is astonishingly easy to use!
Larry McDavid
NASS Sundial Registrar
On 10/31/2014 9:07 AM, Tom Kreyche wrote:
I noticed that a Dipleidoscope is up for live auction on Ebay (USA) - this
seems to be a rare offering (not in my budget!).
http://www.ebay.com/itm/DIPLEIDOSCOPE-/231365300840?ssPageName=ADME:SS:SS:US:3160
LOT 1130
Seller's Estimate: USD 600.0 - 800.0
DIPLEIDOSCOPE - England, 19th century, brass and bronze. Brass and glass
prism mechanism inset into a shaped bronze case with scrolled sides.
Engraved "Dent's Patent Meridian Instrument" and "67 Strand, London". 3"h.
2.25"w. 3"d.
------------------------------
Message: 7
Date: Fri, 31 Oct 2014 11:00:09 -0700
From: Larry McDavid <[email protected]>
Cc: sundial <[email protected]>
Subject: Re: Dipleidoscope on Ebay
Message-ID: <[email protected]>
Content-Type: text/plain; charset="windows-1252"; Format="flowed"
The Dent Dipleidoscope now offered on live auction appears to have a
curious hole or similar detail in the center of the removable round
cover; none of my Dent dipleidoscopes has such a hole in the cover and I
have never seen another one that does. I don't know what that detail
actually is nor its purpose. It could be an "aftermarket" modification!
You surely want the large area of the dipleidoscope exposed when you
place your head to observe the dipleidoscope image.
I have an original printed Dent booklet, with its included tables of
solar noon offset. This booklet is, of course, printed in black and
white. While it does include a drawing depicting how solar rays are
reflected within the dipleidoscope optics, understanding the ray paths
as shown and how they are used is difficult! In my presentation to NASS,
I expanded this drawing with labeled color line paths to help explain
the operation. Once understood, the dipleidoscope is a really simple
instrument!
Attached is a thumbnail image of the demonstration device I used to
depict the image seen in a Dent Dipleidoscope as solar noon approaches.
As I titled my presentation, the Dipleidoscope is a Sundial by Another
Name...
Larry McDavid
NASS Registrar
On 10/31/2014 9:44 AM, [email protected] wrote:
A copy of Dent's booklet on the use and design of the Dipleidoscope is
available on line from Google Books at:
http://books.google.com/books?id=9QlbAAAAQAAJ&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false
Dave
Sent from my iPad
...
--
Best wishes,
Larry McDavid W6FUB
Anaheim, California (SE of Los Angeles, near Disneyland)
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