aussiblu wrote:
"From the book The Farmer's New Guide, 1893

How to Cut Glass - It is not generally known that glass may be
cut, under water, with a strong pair of scissors. If a round or
oval be required, take a piece of common window glass, draw the
shape upon it in a black line; sink it with your left hand under
water as deep as you can without interfering with the view of
the line, and with your right use the scissors to cut away what
is not required."
http://www.backroadhome.com/how-to-cut-glass.html

Well, if it's on the internet...