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 arc put 

 into the lantern this fog does not appear. 



