Re: ATM obsidian

[Bruce Swayze <swayze@europa.com>]

At 09:52 PM 9/23/97 -0700, you wrote:
>
>While on a recent vacation I found some "snowflake" obsidian.
>
>This is the first time I have seen obsidian which does not appear to
>have pits, "micro" cracks or inclusions. My impression, is that the quality 
>of snowflake might be high enough for an astro mirror.
>Has anyone tried this type of obsidian for this purpose?
>
>Of course it will be much cheaper and easier to obtain a pyrex blank
>but then we are having fun and money is no object right?
>
>Comments?
>
>Kreig McBride

A number of years ago, I believe it would have been around 1981 or 1982,
Steve and I went down to Riverside and I remember seeing a 16" dobsonian
made with a homemade obsidian mirror.  To make it the ultimate homemade
instrument, the guy even coated the mirror himself with a silver coating.
Another reason this instrument sticks in my mind is because someone that
year had an image intensifier device (this was long before CCD's) and they
used it that night in this guy's telescope.  There was a write up in one of
the early TM's about the fact that here was an example of the latest in
high-tech gadgetry being used on the most low-tech homemade instrument in
the field.  What a contrast.  I believe, if memory serves me, that Richard
Berry was there and involved with this event.  (Are you reading this
Richard?  Do you remember?  Do I have this story right?)  

Anyway, the point is, you can certainly use this material to make a mirror.


"*-.,_,.-*"`"*-.,_,.-*"`"*-.,_,.-*"`"*-.,_,.-*"`"*-.,_,.-*"`"*-.,_,.-*"`"*-
Bruce Swayze
swayze@europa.com
http://www.europa.com/~swayze    Swayze Optical Home Page 
http://www.europa.com/~swayze/spider.html  Homemade Spider page
"*-.,_,.-*"`"*-.,_,.-*"`"*-.,_,.-*"`"*-.,_,.-*"`"*-.,_,.-*"`"*-.,_,.-*"`"*-.