It takes a long, smooth stroke practiced carefully
over many years and made with one steady motion.

You do not really cut glass, you score its length
with a sharp, revolving wheel at the end of a tool

not much bigger than a pen-knife.  Glass is liquid,
sleeping.  The line you make goes through the sheet

like a wave through water, or a voice calling in a dream,
but calling only once.  If the glazier knows how to work

without hesitation, glass begins to remember.  Watch now
how he draws the line and taps the edge: the pieces

break apart like a book opened to a favorite passage.
Each time, what he finds is something already there.

In its waking state glass was fire once, and brightness;
all that becomes clear when you hold up the new pane.