26 MAGIC LANTERN WITH DIRECT CURRENT [Cn. I 



FIG. 8. STANDARD AMERICAN LANTERN SLIDE, FULL SIZE, WITH 



DIRECTIONS FOR MARKING IT, AND INSERTING IT IN THE 



CARRIER so THAT THE SCREEN IMAGE WILL BE ERECT. 



35. Correct position of the lantern slide in the carrier. In 



order that the image on the screen may be right side up and like the 

 original in every way, the lantern slide must be put into the carrier 

 in the following manner to counterbalance the inverting effect of 

 the projection objective (fig. i). 



1 . A lantern slide with any printing upon it must have the side 



which reads correctly face the lamp, if the screen is of 



ordinary form. 



If the screen is translucent like ground glass and the picture is 

 viewed from the back of the screen, then the printing must face the 

 screen, not the lamp. 



2. In all cases the slide must be put into the holder with the 



bottom edge up (fig. 6, 8). 



