Three parts copper, 1 part zinc, and a small quantity of tin If these metals are pure, and are melted in a covered crucible containing charcoal, the alloy bears so close a resemblance to gold as to deceive very skilful persons.
Tombac, or White Copper, is formed of variable proportions of copper, arsenic, and tin.
Five oz. pure copper, and 1 oz. zinc. The copper must be first melted before the zinc is added.
Prince's Metal is made of from 2 to 3 parts of copper, and 1 of zinc; or of common brass, with an extra portion of zinc.
Two drms. copper, 1 oz. antimony, and 12 oz. tin.
Eight oz. scrap iron, or steel, 1 lb. antimony, and 3 oz. nitre. The iron or steel must be heated to whiteness, and the antimony and nitre added in small portions. Two oz. of this compound are sufficient to harden 1 lb. of tin.
Four and a half lbs. tin, 1/2 lb. bismuth, 1/2 lb. antimony, and 1/2 lb. lead. Or, 100 lbs. tin, 8 lbs. antimony, l lb. bismuth, and 4 lbs. copper This alloy is used for making tea-pots, and other vessels, which imitate silver.
Five and a half lbs. of copper, and 1/2 lb. zinc. The copper must be fused in a crucible before the zinc is added. This alloy is of a red colour, and possesses greater durability than copper.
Ten oz. lead, 6 oz. bismuth, and 4 drms. antimony. Or, 2 lbs. antimony, 8 oz. brass, and 10 oz. tin.
One hundred and twelve lbs. Bristol brass, 14 lbs. zinc, and 7 lbs. block tin. Or, 9 lbs. copper, and 1 lb. tin. Lead was formerly used in this alloy to facilitate the casting, but at the battle of Prague it was found that some of the pieces of ordnance formed of this metal were actually melted by the frequency of firing.
Four oz. lead, and 2 oz. antimony.
Ten lbs. lead, and 2 oz. antimony. The antimony is added while the lead is in a state of fusion. The antimony gives hardness to the lead, and prevents its contraction when cooling. Some manufacturers employ different proportions of these metals, and some add copper or brass.
Nine lbs. lead, 2 lbs. antimony, and 1 lb. bismuth. The antimony and bismuth are added when the lead is melted. This alloy expands in cooling; the mould is, therefore, entirely filled when the metal is cold, and no blemish is found in the letters. Stereotype plates are formed of this alloy. Some manufacturers employ tin instead of bismuth.