The Voltaic Battery.—Electrotype

1850 Scientific American  
The Voltaic Battery •••• Electrotype. NUMBER VII. When metal is deposited by the battery, for the purpose of copying the form of the reci pient, or basis, the process is called electrotype. The Electrotype Art is, theref ore, the art of casting by galvanism; and the suecessful prac tice of electro-casting, like any other mode of casting, consists in making fine impressions and good metal. The mould to reoeive the deposit must be of metal, or, if not of metal, it must have a me tallic face, and
more » ... e tallic face, and should be impervious to water. A great many substances and mixtures have been proposed for moulding: plaster of paris, beeswax, tallow, and spermaceti, and mixtures of wax, tallow, and rosin, in a multitude of proportioni. Before the plaster casts can be used they must be made water-proof, by smo king in hot wax or tallow, unti l all the air is driven out of the casts. If the plaster cast is taken out of the melted wax or tallow, while quite hot, the lluid will soak into the cast and leave the face rough. And if taken out when
doi:10.1038/scientificamerican12071850-91 fatcat:lacy2ib3xvehvk5qv4vkvk4rqm