The usual
negative or mould having been obtained as usual, he prepares a gelatine
mass resembling the hektograph mass, by soaking the gelatine first, then
melting it and adding enough of any inorganic powdered substance to give
it some stability. This is poured into the mould, which is previously
moistened with glycerine to prevent adhesion. When cold, the gelatine
cast is taken from the mould, and is, of course, the same size as the
original. If the copy is to be reduced, this gelatine cast is put in
strong alcohol and left entirely covered with it. It then begins to
shrink and contract with the greatest uniformity. When the desired
reduction has taken place, the cast is removed from its bath. From
this reduced copy a cast is taken as usual. As there is a limit to the
shrinkage of the gelatine cast, when a considerable reduction is desired
the operation is repeated by making a plaster mould from the reduced
copy, and from this a second gelatine cast is taken and likewise
immersed in alcohol and shrunk. It is claimed that even when repeated
there is no sacrifice of the sharpness of the original.
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