THE BOOK OF THE LANTERN.
231
It will then soon be seen which of the lettered spaces has
received the correct exposure ; and a memorandum noting
time and distance of lens from screen can either be
attached to the negative, or entered in a book against a
number corresponding with a number scratched on the
glass negative.
The same principle can be applied to contact printing
in a frame on bromide paper, by gas or lamp light. When
the frame has been charged with its negative and the
bromide paper, support it upright at a distance of, say,
18 inches from the turned-down flame. Now, place
in front of it an opaque card, sufficiently large to more
than cover the frame. This card should have a hole about
1 inch in diameter cut in it in one corner. Turn up the
light and expose for five seconds. Alter the position of the
hole and give ten seconds, and so on. When the paper is
subsequently developed the several exposures can be
readily identified, and the negative can be labelled to the
effect that it requires so much exposure at a given distance
from a flame. Thus—Bromide paper, 18 in. 25 sec. This
negative will then be an infallible guide for the exposure
of negatives of a similar type; for a systematic worker,
unless he be quite a beginner, will fall into the way of
producing negatives of much the same character and
strength, and printing from them by lamp light will then
become an easy matter to him.
After this somewhat long but not unnecessary digression,
I will resume my directions for enlarging on bromide
paper, and for the sake of simplicity will suppose that the
operator is not supplied with the special form of easel