grinding mirrors

To All you lens makers here is a question. Could a drop of water been
mans first lens"? Bert

(G=EMC^2 Glazier) wrote in news:21906-3F67629C-553
@storefull-2355.public.lawson.webtv.net:

To All you lens makers here is a question. Could a drop of water been
mans first lens"? Bert



I would suppose the lenses in our eyes were the first used by man ;-).

Actually not many amateurs make lenses. Mirrors are a lot easier - only one
surface to grind, polish and figure and no worries about wedge.

llanzlan.

(G=EMC^2 Glazier) wrote in news:21906-3F67629C-553
@storefull-2355.public.lawson.webtv.net:

To All you lens makers here is a question. Could a drop of water been
mans first lens"? Bert



I would suppose the lenses in our eyes were the first used by man ;-).

Actually not many amateurs make lenses. Mirrors are a lot easier - only one
surface to grind, polish and figure and no worries about wedge.

llanzlan.

Seems the first mirror could be,a girl looking in a pond with a dark
sandy bottom,and checking out her hair. Well they tell us glass is a
liquid. Bert

Seems the first mirror could be,a girl looking in a pond with a dark
sandy bottom,and checking out her hair. Well they tell us glass is a
liquid. Bert

Bert posted:

Well they tell us glass is a
liquid.

Who are 'they'? Glass is a solid.
--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 10th Annual NEBRASKA STAR PARTY *
* July 27-Aug. 1st, 2003, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************

Bert posted:

Well they tell us glass is a
liquid.

Who are 'they'? Glass is a solid.
--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 10th Annual NEBRASKA STAR PARTY *
* July 27-Aug. 1st, 2003, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************

David They that told us glass is a liquid were people that looked at
glass that was standing on edge and its bottom had spread out.These
large glass panes were used for churches and were hundreds of years old.
I read this a few times many moons ago. I don't believe everything
"they" that write the books tell me,and like you I think glass is a
solid. I should know with a last name of "Glazier" Bert
PS Knew you would jump on this David and that is why I posted it.

David They that told us glass is a liquid were people that looked at
glass that was standing on edge and its bottom had spread out.These
large glass panes were used for churches and were hundreds of years old.
I read this a few times many moons ago. I don't believe everything
"they" that write the books tell me,and like you I think glass is a
solid. I should know with a last name of "Glazier" Bert
PS Knew you would jump on this David and that is why I posted it.

Bert posted:

They that told us glass is a liquid were people that looked at
glass that was standing on edge and its bottom had spread out.These
large glass panes were used for churches and were hundreds of years old.
I read this a few times many moons ago.

Bert, this is a stupid urban legend. The glass panes were thicker on the
bottom than on the top because THAT WAS THE WAY THEY WERE CAST!!! They did
*not* flow. For the details go to the following URL:
http://www.glassnotes.com/WindowPanes.html

--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 10th Annual NEBRASKA STAR PARTY *
* July 27-Aug. 1st, 2003, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************