From: "Bob May" 
To: "atmlist" 
Reply-To: "Bob May" 


That picture of the 6" further down the page shows the Twyman effect
to good effect!  A nice little raising of the broken edge is what Twyman
described as to what happens when you cut or otherwise disturb a finished
optic.  A few cuts with a lap will quickly take that down without too much
trouble. The pits look exactly right.  They are all kinds of little cracks
that happen when the grit digs into the glass.  The next little bit of fun
will be to follow the pits down through the grits, the AlO grits make a
different kind of pit, and through the polishing stages. Bob May
http://nav.to/bobmay
bobmay{at}nethere.com
NEW! http://bobmay.astronomy.net

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