Ch. VIII]
PREPARATION OF LANTERN SLIDES
219
§ 339. Troubles in making lantern slides.—These are the
troubles liable to be met in photography. They must be over¬
come by following intelligently the directions for photographic
work in general and for lantern-slide making in particular. Study
the directions coming with the lantern-slide plates used.
In making written slides or diagrams on varnished slides the pen
will not work well, and the ink will crawl if the varnish is not dry.
Fig. 120. The Moler Sectional Lantern-Slide Cabinet.
(Cut loaned by G. S. Moler).
This cabinet holds 1200 lantern slides. It consists of a box with twenty
vertical, sliding frames, each frame holding 60 slides.
In the picture the cabinet is shown on a table. One of the frames is entirely
removed and leans against the table leg. One frame is pulled out for examin¬
ing the slides stored in it.
In coloring lantern slides one must learn to use colors which give
the correct effect with the artificial light used in projection. A tint
which does not seem right by daylight may give exactly the desired
effect by lamp-light. This is why the advice is given to test the
work frequently in the lantern.
Remember that there is more danger of getting the lantern
slides too opaque than not opaque enough.
Sometimes when being exhibited a lantern slide shows a mist or
fog spreading over it. This may partly or wholly disappear.
This is a real fog, and comes from the moisture in the slide, or its
mounting. If the slides are thoroughly dried before they are put
into the lantern this fog does not appear.