ATM Listen to yourself...

[Archer Sully <archer@meer.net>]

Off and on, mostly off, I've been working on a 6" f/6.66
scope for the last 2 years (hey, I said it was mostly off).
After finally achieving a nicely polished sphere and building
a tester, I got in a hurry and didn't build a proper test
stand, deciding to just make do with a music stand.  I 
think you can all see what's coming...

I should mention that I have been dropping things constantly
for the last few days... pitch laps, watches, small children.
I should have listened to the warning.

Anyway, I put the mirror-holder on the stand (one of those
sturdy black music stands, but not a Manhasset) turn around
and CLANG! my mirror hit the floor!  Oddly enough, I don't
believe that a single piece of glass actually came off.  
Instead, there are these really neat looking fractures in
the edges where it hit the basement floor from a height
of ~1 meter.

These fractures are really interesting.  They go to the edge,
but not through.  There are visible "rainbows" inside the
glass along the edges of the fractures.  One is really large,
going from the edge of the polished surface diagonally back 
through the glass to about 1/2" in.  The length forms a 
3" chord.  There's a smaller fracture zone (1" x 1/4" or so)
diametrically opposite.  I think that the mirror fell off
face first, rotating slightly forward to hit on the edge of 
the chamfer, and then fell forward onto its face.

I strongly suspect that this mirror holder will never become
a full fledged mirror, although it might be fun to use it
to practice chemical silvering and use it for shaving.

Oh well, I really should have been making an 8" (excuse me,
200mm) anyway ;-)

Archer Sully
Boulder, CO