3. The type-metal is prepared for immediate use by melting it, as fast as it may be needed, in a small crucible, over a coal fire. The caster having placed the matrix in the bottom of the mould, commences the operation of casting by pouring the metal into the mould with a small ladle. This he performs with his right hand, while with the other he throws up the mould with a sudden jerk; then, with both hands he opens it, and throws out the type. All these movements are performed with such rapidity, that an expert hand can cast about fifty types of a common size in a minute. Some machines have been lately introduced, which operate with still greater rapidity. 4. Each type, when thrown from the mould, has attached to it a superfluous portion of metal, called a _jet_, which is afterwards broken off by hand. The jets are again cast into the pot, or crucible, and the types are carried to another room, where the two broad sides are rubbed on a grindstone. They are next arranged on flat sticks about three feet long, and delivered to the _dresser_, who scrapes the two sides not before made smooth on the grindstone, cuts a groove on the end opposite the letter, and rejects from the row the types which may be defective. 5. The whole process is completed by setting up the types in a printer's composing-stick, and tying them up with packthread. Much of the work in the type-foundry is performed by boys and females. In the preceding cut are represented a man casting types at a furnace, and a boy breaking off the jets; also two females rubbing types on a large grindstone. The fumes arising from melted lead in the casting-room are considered deleterious to health. 6. Various sizes of the same kind of letter are extensively used, of which the following are most employed in printing books--Pica, Small Pica, Long Primer, Bourgeois, Brevier, Minion, Nonpareil, Pearl, and Diamond. A full assortment of any particular size is called a _fount_, which may consist of any amount, from five pounds to five hundred, or more. The master type-founder usually supplies the printer with all the materials of his art, embracing not only types, leads, brass rules, and ordinary ornaments, but also cases, composing-sticks, galleys, printing-presses, and other articles too numerous to be mentioned. 7. The inventor of the art of casting types was Peter Shoeffer, first servant or workman employed by Guttemburg and Faust. He privately cut a matrix for each letter of the alphabet, and cast a quantity of the types. Having shown the products of his ingenuity to Faust, the latter was so much delighted with the contrivance, that he made him a partner in the printing business, and gave him his only daughter, Christina, in marriage.