User Links for
 Craig







CURRENT MOON
(North America)
Telescopes
Item: 
Dogson
Brand: home made
Acquired Date: 11/30/-0001
Description: 

Hmmnnn: not sure how this entry's going to come out --nor how to upload the photos which go with it. So I'll just take a stab at it.

~~~~~~~~~~~~~~~~~~
 
This telescope, without my knowing how it would end up, has been going through design changes for 57 years --since I was 14 years old, and it has yet to mature into a satisfactory finished 'scope. The only things which havn't changed since my initial equatorial mount effort is that it remains a long focus, alt-azimuth, Newtonian instrument, embodied in a closed tube --and a rectangular one these past 20-odd years. The accompanying photos reveal extra holes and scars which attest to mistakes, redesigns and modifications --in the Dogson's long struggle to be born.
 
"Dogson-1" and the forth-coming "Dogson-2" have had many designations --up to the recent "DS-16b2". Now that the design seems to have finally stabilized, best I'd recognize/admit that this is only the second "roll-out" in 13 years --by calling it the "DHS-2A1" (and, as ever: "Dogson-2" or just "D2").
 
The "DHS" part recognizes and appreciates Mr. Holcombe's and Mr. Sellers' priority (see below), while the "A" designates my original aim point of a smaller field "planetary" 'scope (a 0.85 degree field, a nominal one inch secondary, a 3mm exit pupil --with a humble 43 degree x 25mm Plossl ocular).
 
The "B" version (if ever built) will simply have a larger (1.3 inch) secondary, an inch more of cross section, nearly a 1.4 degree field (using a humble, 43 degree, 40mm Plossl ocular) and nearly a 5mm exit pupil.
 
--insert photos and legends (somehow)--
 
However it was to come out, I wanted my telescope to be simple, stable, humbly practical, and easy for others to build.
 
I'd been inspired by the obvious stability of classic mounts like those of Hadley's, Herschel's, and Lord Rosse's telescopes, but especially by F. J. Sellers' 1920s design, which our regional discussion and construction group: "The Toledo Scope Works", took a look at some time ago. (The helpful, pleasant and resourceful folks at the Scope Works are the reason I was able to resume my old passion for astronomy and telescope making. They've been supplying me with ideas, software, encouragement, and components for years. David made the mirror and Chuck made the Crayford focuser for Dogson-1.)
 
** A newer fellow at the Skopewerke, Mel Bartels (who goes way way back with the Oregon ATM scene, plus he has a great presence among our literature and web sites --including his own) --has alerted me that this type of mounting goes back much further than Sellers. It was invented by the first manufacturer of telescopes in the United States: Amasa Holcomb, who you can read about at:
 
> http://www.bbastrodesigns.com/HolcombeMount.html
 
> http://labbey.com/Articles/Mason/Largest.html
 
> http://en.wikipedia.org/wiki/Amasa_Holcomb
 
Holcomb was a self-tought American Renaissance man who lived a long life and made great use of his time. He started making telescopes later in life, purely for the love of doing so, but ended up filling many orders from private and institutional clients. There are a number of observatories which still bear his name.
Use: 
Hmmmnnnn some more.
 
 
I'll have to look again at others' journal entries and see how the photo content is handled.
 
 
'Bye for now,
 
Craig
 


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