428 PRECAUTIONS FOR MOVING PICTURES [Cn. XI 



i. e., see that the pictures are evenly spaced. (3) The sprocket 

 holes match evenly. (4) That the patch is strong and no loose 

 corners stick up. 



If the patch is not good in all these particulars, it must be 

 remedied. 



There should be no torn sprocket holes or torn places in the film 

 or bad scratches in the emulsion. If any such defects are found, 

 they should be cut out and the film patched together again. Places 

 may be found where the film broke and was pinned together. 

 Remove the pin and cement the film. 



When the whole film has been inspected in this way, rewind it, 

 so that it will go through the machine correctly. 



See that there is a "leader" or strip of blank film i to 2 meters 

 (4 to 5 ft.) long to thread through the machine, so the entire title 

 of the film may be shown. The part of the film used to thread the 

 machine often becomes broken and a good "leader" saves the film 

 itself from damage. 



If there is time, it is well to run the film through the machine and 

 watch the screen picture before showing it to an audience. 



594. Splicing the film. When moving pictures are to be 

 shown the operator will need to patch the film occasionally. Often 

 a film breaks or an old splice comes in two. A splice is made 

 by cementing the two ends of the film with "Film Cement." 



Cut one end of the film, b, (fig. 235), exactly on the line between 

 two pictures and scrape the back (shiny side) of the film with a 

 sharp knife. There may be oil on the film. It must be removed; 

 cement will not hold otherwise. Cut the other end of the film a, 

 about 4 mm. (}/% in.) longer than a dividing line between two pic- 

 tures. Then scrape off the emulsion between the picture division 

 and the ends of the film. This emulsion can be scraped off 

 accurately to the line by holding a straight edge over the picture 

 on a, and letting the end of the film project. Scrape the emulsion 

 off and right down into the film stock. Scrape the corners as well 

 as the middle, as the corners usually are the first to work loose. 

 Film cement is then spread on the back of b, and the front of a, 

 with a brush or stick, never use the fingers. Be sure to get plenty 



