34 MAGIC LANTERN WITH DIRECT CURRENT [Cn. I 



Af, 45 degree mirror to reflect the parallel beam vertically. 



C, Second element of the condenser in a horizontal position. The lantern 

 slide is put just above it. 



O Projection objective in a vertical position for opaque projection. 



M 45 degree mirror above the objective to reflect the light horizontally 

 to the screen. 



G Vertical support for the condenser, objective and mirror. 



E Lantern front holding the objective. 



E 2 Set screws for holding the objective in position when once centered. 



M Mirror in horizontal position. When raised 45 it serves to reflect the 

 horizontal beam down upon an opaque object. 



C 2 Second element of the condenser used in projection with the microscope 

 or lantern objective with the object in the ordinary vertical position. 



S Opening for the lantern slide carrier. 



Z>, Objective and its holder. 



O Projection objective for lantern slides. 



FFF Supports of the condenser, etc. 



N Platform on which opaque objects are placed. 



J5 i; 2 Legs or supports of the prismatic rod serving as an optical bench. 



PROJECTION WITH MULTIPLE LANTERNS 



In the period before the common use of the moving picture 

 machine, when the pictorial effect was dependent wholly on the 

 magic lantern, two and even more lanterns were run simultaneously 

 i. c., both were going all the time. 



43. Composition of multiple lanterns. 



1. Each lantern must be complete in itself. 



2. The size of image of each lantern must be exactly the same. 



3 . The lanterns must be so placed and so inclined toward each 



other that the light discs on the screen exactly coincide. 

 They are now usually placed one above the other (fig. 17). 



44. Wiring for multiple lanterns. Each lantern must have 

 its own electric lamp. When the supply is no volts or less each 

 lamp must be separately wired, and each lamp must also have its 

 own rheostat and double-pole knife switch (fig. 2,3). 



In case the supply is 220 volts, each lamp may be separately 

 wired as just described; or both lamps may be put in series, i. e., 

 along one wire, on one system of wiring, and use but a single 

 rheostat. 



45. Use of multiple lanterns. By the use of two lanterns 

 there is not shown first one slide and then another simply, but one 



