434 MOVING PICTURE EXHIBITION [Cn. XI 



(4) See that the optical parts are clean, and free from dust. 

 See that everything is in line and the light is even on the screen. 



(5) See that the objective is in focus. 



(6) See that the mechanism is oiled and in good order, no screws 

 loose. 



(7) See that the films are properly mended and that there are 

 no misframes. 



(8) See that the rolls of film are in the proper order. 



The first reel of film is put in the magazine and the machine is 

 threaded. 



The arc is either pushed away from the operator so it will not 

 shine on the moving picture head or else the dowser in front of the 

 condenser is let down. 



The arc lamp is lighted. When all is ready the crank of the 

 machine is started, the arc lamp pulled toward the operator into 

 position, the dowser is raised, and the house lights turned off 

 all at the same time. 



During the exhibition there should be but two things to watch. 



1. The adjustment of the carbons. The carbons need occa- 

 sional attention to keep a good light. 



2. The action on the screen. The action on the screen should 

 be very carefully followed. It will serve as a guide to the proper 

 speed to turn the crank of the machine. The lighting of the picture 

 and the focus of the objective may need attention occasionally as 

 can be seen by watching the screen. 



If the machine or the film is poor various mishaps may occur and 

 require a short stop. 



The most frequent is a misframe. This occurs when a .patch 

 has not been properly made and the pictures not properly matched. 

 The difficulty is remedied by raising or lowering the framing lever. 

 Note the place where the misframe occurs and remove it before the 

 film is shown again. , 



The film may, break. Turn off the light instantly, or push the 

 lamp over to the lantern-slide side or lower the dowser. If a tag 

 end of film is left in the aperture plate, it may catch fire if the light 

 is not turned off. The film is now threaded through the machine 



