Domestic Encyclopædia (1802)/Supplement/Brass

BRASS.—In 1781, a patent was granted to Mr. James Emerson, for his invention of making brass of copper and zinc.—The patentee directs the spelter to be melted in an ron boiler, then passed through a perforated ladle, and placed over a vessel containing water; by which means the zinc will be granulated. Fifty-four pounds of copper shot are now mixed with 10lbs. of calcined and pulverized calamine, together with about one bushel of charcoal: a handful of this mixture is first put into a casting-pot, then 3lbs. of the granulated zinc; upon which the composition before specified is laid till the vessel be filled: Mr. E., however, has not stated the exact proportion of the ingredients.—Eight similar pots are now to be supplied with the same materials, and the whole must be submitted to the heat of a furnace, for the space of 12 hours; when the process will be completed, and 82lbs. of brass be procured; which the patentee asserts to be of a very superior quality to that manufactured from copper and calamine.