the Birmingham Photographic Society. Reported in the
_Photo. News_.]

There can be no question that there is no plan that is so simple for
producing transparencies as contact printing, but in this, as in other
photographic matters, one method of work will not answer all needs.
Reproduction in the camera, using daylight to illuminate the negative,
enables the operator to reduce or enlarge in every direction, but the
lantern is a winter instrument, and comes in for demand and use during the
short days. When even the professional photographer has not enough light to
get through his orders, how can the amateur get the needed daylight if
photography be only the pursuit in spare time? Besides, there are days in
our large towns when what daylight there is is so yellow from smoke or fog
as to have little actinic power. These considerations and needs have led me
to experiment and test what can be done with artificial light, and I think
I have made the way clear for actual work without further experiment. I
have not been able by any arrangement of reflected light to get power
enough to print negatives of the ordinary density, and have only succeeded
by causing the light to be equally dispersed over the negative by a lens as
used in the optical lantern, but the arrangements required are somewhat
different to that of the enlarging lantern.

The following is the plan by which I have succeeded best in the production
of transparencies:

[Illustration]

B is a lamp with a circular wick, which burns petroleum and gives a good
body of light.

C is a frame for holding the negative, on the opposite side of which is a
double convex lens facing the light.

D is the camera and lens.

All these must be placed in a line, so that the best part of the light, the
center of the condenser, and the lens are of equal height.

The method of working is as follows: The lamp, B, is placed at such a
distance from the condenser that the rays come to a focus and enter the
lens; the negative is then placed in the frame, the focus obtained, and the
size of reduction adjusted by moving the camera nearer to or further from
the condenser and negative. In doing this no attention need be paid to the
light properly covering the field, as that cannot be adjusted while the
negative is in its place. When the size and focus are obtained, remove the
negative, and carefully move the lamp till it illuminates the ground glass
equally all over, by a disk of light