ATM Testing optical flats

[Dan Cassaro <dcass@mediaone.net>]

Re: my earlier message about testing a 16" optical flat...
Has anyone actually tried the water test?  Apparently, you use a  very
still container of water to form a perfect flat. (Well, I suppose it is
just a tiny bit concave due to the earth's curvature).
This was described sometime back in S&T in an article by Ed Jones.
I've dug through my collection and the ATM archives, but can't find the
month/year....  Is there a comprehensive guide to S&T on the web
somewhere?
Thanks for all the responses,
Dan Cassaro