Sheet-glass.
In the
Continental method of making sheet-glass, — introduced into
England in 1850 by Chance Brothers,
Birmingham, on the occasion of the construction of the
World's Fair Expo-
[
2143]
sition building by
Sir Joseph Paxton, — the workman takes up a quantity, some 12 or 14 pounds of the semi-fluid material from the meltingpot upon the end of his tube, and elongates it by rolling upon a wooden table; he then blows it into an elongated spheroidal form, and then swings it around in a vertical circle, reheating it two or three times, until the end not attached flies open and the glass assumes the form of a hollow cylinder.
The cylinders are cut longitudinally with a diamond, and placed in a furnace, where they open out into sheets under the influence of heat.
Glass made in this way is also known as
cylinder, broad, spread, German glass.
(See cylinder-glass.) The composition is the same as
crown-glass.
|
Flattening the sheet. |
Figs. 4958,
4959, show the various operations and the conditions of the glass in the various stages.