ff the original
after solidifying, and at the same time to retain the sharpness of the
mold.

The molding medium of plaster composition in a semi-liquefied state is
then poured on to the original in the molding frame. The surplus
plaster is scraped off flush with the top of the molding frame.

After the plaster matrix in its molding frame has set sufficiently it
is released by means of cams from the working pattern on the
molding-slab.

The plaster matrix is then placed in a drying oven, through which a
forced draft of hot air is kept circulating at high pressure. The
thorough drying of the mold takes approximately ninety minutes.

When the plaster mold has become sufficiently dried, a round hole is
cut through the bottom of the matrix in an offset of the molding
frame. This hole is the gate through which the molten aluminum is
forced. The mold is then securely locked upright in a specially
designed casting machine.

The Aluminotype is cast by pressure and not by pouring as in the case
of stereotypes, which depend entirely upon gravity. Fused aluminum
alloy is poured into a hopper on the casting machine. A piston
operated by the agency of compressed air forces the aluminum evenly
into all parts of the plaster matrix.

When the cast is completed the molding frame is taken from the casting
machine and the Aluminotype removed from its plaster-of-paris matrix.

_AUTHORITIES_:

"An Outline of the History of Printing," by R. A. Peddie.

"Typographical Printing Surfaces," by L. A. Legros.

"Manual of Electro-Metallurgy," by Napier.

"The Encyclopedia Brittanica."

"Electrotyping and Stereotyping" Typographical Technical Series, Vol. XV.

The Rapid Electrotype Company.

THE MAKING OF THE FOOLPROOF NEWSPAPER DRAWING

SOME ADVERTISING PICTURES PRINT WELL--OTHERS DO NOT. WHY? IT'S ALL A
MATTER OF GOING ABOUT IT IN A KNOW-HOW WAY

_By J. LIVINGSTON LARNED_

An advertiser--perhaps one of the largest users of newspaper space in
the country--sprang a surprise recently on his ad-manager. Into the
office he came, one day, grim-visaged, jaw set, fire in his eyes, and
armed with no less than fifty clippings from exchanges.

And on the amazed ad-manager's desk he placed two conglomerate piles
of advertising matter. One represented the national newspaper campaign
of his own industry; the other a collection of newspaper
advertisements, picked at random.

"I think I have conclusive proof," said he, in no mil