to a plate of copper and also dipped into a liquid, when the current
passes, the metal will be decomposed and deposited in a uniform layer
over the article at the negative electrode. This process is called
_electro-plating_.


What is Electrotyping?

It is the process of copying medals, type, wood-cuts, engraved copper
and steel plates, etc., by means of electrical deposition. It is
chiefly used for making, from the ordinary movable types, plates of
fixed metallic types, for printing books.


Describe the process.

The article to be copied is first covered with black-lead, and then a
mould is made of it in wax or gutta-percha. This mould is placed in a
solution of sulphate of copper, and attached to the negative pole of
the battery, while a plate of copper is hung from the positive pole.
The electric current decomposes the copper, which is deposited in a
thin film upon the mould. This film is removed and stiffened by being
backed with metal.


What is the difference between Electrotyping and Stereotyping?

In stereotyping, a plaster of Paris mould is taken from the types, and
upon this mould melted type-metal is poured, which, when hardened,
makes a solid plate.