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Alloys (Put into a crucible lbs)

Put into a crucible 5 lbs. of copper; when fused add lb. of zinc; these metals will combine, forming an alloy of a reddish color, but possessing more lustre than copper, and also greater durability. White Tombac.

When copper is combined with arsenic, by melting them together in a close crucible, and covering the surface with common salt to prevent oxidation, a white brittle alloy is formed. Common Pewter. adopt different compositions for stereotype plates.

Some form an alloy of 8 parts of lead, 2 parts of antimony, and part of tin.

Mode of Casting.

For the manufacture of stereotype plates, plaster of Paris, of the consistence of a batter-pudding before baking, is poured over the letter-press page, and worked into the interstices of the types with a brush. It is then collected from the sides by a slip of iron or wood, so as to be smooth and compact. In about 2 minutes the whole mass is hardened into a solid cake. This cake, which is to serve as the matrix of the stereotype plate, is now put upon a rack in an oven, where it undergoes great heat, so as to drive off superfluous moisture. When ready for use, these moulds, according to their size, are placed in flat cast-iron pots, and are covered over by another piece of cast-iron perforated at each end to admit the metallic composi- The best sort of pewter consists of 100 parts of tion intended for the preparation of the stereotype tin, and 17 of regulus of antimony .

Melt in a crucible 7 lbs. of tin, and when fused throw in 1 lb. of lead, 6 oz. of copper and 2 oz. of zinc. This combination of metals will form an alloy of great durability and tenacity; also of considerable lustre. Best Pewter.

Hard Pewter. plates. The flat cast-iron pots are now fastened in a crane, which carries them steadily to the me- Melt together 12 lbs. of tin, 1 lb. of regulus of tallic bath, or melting pot, where they are imantimony, and 4 oz. of copper. Common Solder.

Put into a crucible 2 lbs. of lead, and when melted throw in 1 lb. of tin. This alloy is that generally known by the name of solder. When heated by a hot iron and applied to tinned iron with powdered rosin, it acts as a cement or solder; it is also used to join leaden pipes, etc.

Hard Solder.

Melt together 2 lbs. of copper, and 1 lb of tin.

Soft Solder.

Melt together 2 lbs. of tin, and 1 of lead. The lining of tea chests makes a good solder for tin ware, being made of tin and lead in about the proper proportions.

Gold Solder Consists of 24 parts gold, 2 silver, and 1 of copper. Silver Solder.

Hard-4 parts of silver to 1 of copper. Soft- 2 parts of silver to 1 of brass wire.

Shot Metal.

Lead, 1000 parts; metallic arsenic, 3 parts.

Printers' Types.

Put into a crucible 10 lbs. of lead, and when it is in a state of fusion, throw in 2 lbs. of antimony; these metals, in such proportions, form the alloy of which common printing types are made. The antimony gives a hardness to the lead, without which the type would speedily be rendered useless in a printing press. Different proportions of lead, copper, brass, and antimony, frequently constitute this metal. Every artist has his own proportions, so that the same composition cannot be obtained from different foundries; each boasts of the superiority of his own mixture.

Small Types and Stereotype Plates.

Melt 9 lbs. of lead, and throw into the crucible 2 lbs. of antimony and 1 lb. of bismuth; these metals will combine, forming an alloy of a peculiar quality. This quality is expansion as it cools, it is therefore well suited for the formation of small printing types (particularly when many are cast together to form stereotype plates), as the whole of the mould is accurately filled with the alloy; consequently there can be no blemish in the letters. If a metal or alloy liable to contract in cooling were to be used, the effect of course would be very different.

Another. The proprietors of different foundries mersed and kept for a considerable time, until all the pores and crevices of the mould are completely and accurately filled. When this has taken place the pots are elevated from the bath by working the crane, and are placed over a water trough, to cool gradually. When cold the whole is turned out of the pots, and the plaster being separated by hammering and washing, the plates are ready for use; having received the most exact and perfect impression.

White Metal.

Melt together 10 oz. of lead, 5 oz. of bismuth, and 4 drs. of regulus of antimony.