mentioned, this dotting machine is capable of producing, theoretically,
360 yards per 10 hours; but practically this production is reduced to
about 250 yards, which, however, is sufficiently satisfactory.

* * * * *




THE REPRODUCTION AND MULTIPLICATION OF NEGATIVES.

By ERNEST EDWARDS, B.A.


A question, relative to the subject of reproducing negatives, which was
put at a meeting of one of your New York societies, prompts me to make a
few remarks on the subject.

Among the numerous and widely diversified ramifications of our business
(the Heliotype Printing Company) we have very often to reproduce and
multiply negatives in both a direct and reversed form. Various methods
for doing this have been tried, and I may here say that I am quite well
aware of all the methods that have hitherto been suggested for the
purpose, but that which I am to describe is the one to which preference
has been given, and which is that known as the carbon process.

A sheet of carbonized paper or "tissue," having been sensitized by
immersion in a bath of bichromate of potash, is dried in the dark and
placed away for future use, although it is undesirable that it be kept
for more than four or five days. This is placed in a printing frame in