Re: ATM Re: Newton's Telescope

["Barlow Pepin" <atmjedit@conceptsnet.com>]

Hey I like this thread, but then I'm a history nut.

1) Hmm... no, the Gregorian was not named after a Pope.  Anything "Gregory"
is Gregorian, like Dobson is Dobsonian -- and in this case it was the
Scottish optician Gregory, author of Optica Promota.

2) Thanks for correcting me on Newton's focal length -- 25 inches is correct
all right. One point however -- Newton's original specs as quoted and
published by King are for Newton's first actual reflecting prototype. The
one in the Royal Society collection, an original, of which numerous replicas
exist, is not this original telescope but Newton's second one. The first
disappeared shortly after it was made, as noted by King.




-----Original Message-----
From: Ron Dyvig <rondyv@gwtc.net>
To: Frank Ward <thewards@mindspring.com>
Cc: ATM LIst <ATM@shore.net>
Date: Thursday, December 09, 1999 5:58 AM
Subject: Re: ATM Re: Newton's Telescope


>
>Frank Ward Wrote:
>
>>Is that because it was named after a pope?, or because of the longer
>focal
>length?
>>FW
>
>     Apparently the design was chosen for economic reasons.  It was much
>less expensive to produce a concave secondary.  More information can be
>found at:
>
>http://clavius.as.arizona.edu/vo/
>
>Ron Dyvig
>
>