s drawn
along the inside of the cylinder and opens it out flat. If there are
any imperfections in the glass the cutter plans to have them come as
near the edge of this opening as possible so there will be little
waste."

Jean nodded.

"Now, as you will see, the glass is ready for the flattener. First he
warms it in the flue of his furnace and then, using his croppie or
iron, he puts it on the flattening-stone; if you look carefully you
will see that the top of this stone is covered with a large sheet of
glass. In the heat of the furnace the cylinder with the split uppermost
soon opens out and falls back in a wavy mass. See?"

Jean watched intently as the great roll of glass unfolded and spread
into billows. The moment it was fairly open the flattener took his
polissoir, a rod of iron with a block of wood at one end, and began
smoothing out the uneven sheet of glass into a flat surface. At times
he had to rub it with all his strength to straighten it. This done the
flattening-stone was moved on wheels to a cooler part of the furnace
and the sheet of glass upon it was transferred to a cooling-stone. When
stiff enough it was taken off and placed either flat or on edge in a
rack with other sheets.

So the process went on.

Cylinder after cylinder was blown, opened up, flattened, and annealed.
So quickly did the single sheets of glass cool that it was not much
more than half an hour from the time they entered the flattening kiln
before they came out thoroughly annealed. They were then carried to the
warehouse for inspection and the especially fine ones were selected to
be polished into patent glass. The sheets were rated as bests, seconds,
thirds, and fourths, and their average size was 48 x 34 or 36 inches,
although the foreman said that sometimes sheets as large as 82 x 42 or
75 x 50 had been made. These, however, were exceedingly difficult to
handle, as they were in constant danger of being broken. The mass of
glass was also very heavy for the blower to wield.

"The great advantage of sheet glass over crown glass is that it can be
made in large pieces. Of course it is not as brilliant as crown, but it
is much more useful," added the workman.

"What is crown glass?" whispered Jean to Giusippe.

"It is a variety of glass manufactured by another process," was the
reply. "We do not make it here. Do you remember the bull's eye glass
windows we saw in England? Well, each of those bull's eyes came from
the center of a