When the glass is made, and its temperature so reduced that it is in a doughy or pasty state, it is then worked off by the blowers into either sheets or tables, as is desired. The blowing of sheet and crown glass is a work of considerable difficulty and labour, and one which cannot be successfully performed, except by a workman who has been brought up from boyhood in a glass-house. A quantity of the soft glass is collected or gathered on the end of a blowpipe, and the workman then blows into it, and distends it into a globular form. Now it is necessary, in making sheet glass, that that globular form should be elongated; the workman therefore holds his blowpipe, which is about five feet long, in a vertical direction, and the softened globe becomes pear-shaped. By dexterously swinging the blowpipe from side to side, which he does while standing on a plank placed over a sort of pit, and by causing it to rise on either side, he converts the pear-shape into a true cylinder, having rounded ends. When the cylinder has assumed the exact shape desired, he places his thumb on the end of the blowpipe, and holds the opposite end of the cylinder in the mouth of the furnace. The glass softens at the heated end, and the expanding air causes it to burst the opening. It is then shaped with a suitable tool, so that it is of the diameter of the cylinder. When the latter is cooled, a piece of hot glass is applied to its shoulder with a pontee, and is drawn out into a thread around it. This makes the glass hot. The thread of glass is removed, a cold instrument is applied rapidly, and the shoulder of the blowing is cut off. The glass is next detached from the blowpipe, and its ends removed, and it is then annealed for a short time, and cut down lengthways internally by a diamond. It is afterwards placed, with the long cut uppermost, in what is called a flattening kiln, that is, in a sort of oven or furnace heated to a high temperature and having a perfectly smooth stone floor; after a short exposure the glass softens, and a workman, with suitable wooden tools, opens it out where it was cut by the diamond, and causes it to lie flat upon the stone. It is then rubbed by a wooden tool, and in this way is flattened, removed from the flattening stone kiln, and placed in a hot chamber, in which it is allowed to cool slowly, for the purpose of "annealing."