One of the key fringe benefits of my work is getting to see other trades at work.  And the very best part is seeing the brilliant, magical techniques that other tradespeople regard as completely routine. The other day I had to pick up a piece of laminated glass from Sarno Glass and Mirror in Hyde Park, MA.  We were making a door for a medicine cabinet (for the third time, but that’s another story), and we needed to use safety glass so that a slipping client wouldn’t bump into the cabinet, break the glass, and sever an artery.  There are two kinds of safety glazing — laminated and tempered glass.  Tempered glass is a pain, as it has to be cut first, and then…