CH. XI] MOVING PICTURES 391 



551. For the historical development of moving pictures see 

 under History in the Appendix. 



For works on moving pictures see: Cyclopedia of Motion 

 Picture Work, 2 vols.; Hepworth, C. M., Animated Photography; 

 Hop wood, Living Pictures ; Jenkins, C. F., Handbook for Motion 

 Pictures and Stereopticon Opera; Jenkins, C. F., Picture Ribbons; 

 Richardson, F. H., Motion Picture Handbook, 2d ed.; Talbot, 

 F. A., Moving Pictures; Hints to Operators by the Nicholas 

 Power Company; Periodicals on Moving Pictures, e. g., the Mov- 

 ing Picture World and catalogues of manufacturers and dealers 

 in moving picture outfits. 



INTRODUCTION 



552. The steps that had to be taken in human experience and 

 knowledge before it was possible to have moving pictures at all, 

 were many ; and the time between some of the steps was very long. 



The first step was a knowledge of the physiology of vision, and 

 especially a knowledge of the persistence of visual impressions. 

 Primitive man knew that a glowing torch would make a circle of 

 fire if it were whirled around rapidly enough. He knew also that he 

 could see objects illuminated by an instantaneous flash of lightning. 



From this power of seeing by an instantaneous illumination, and 

 the persistence of the impression for a limited time after the light 

 has gone, arise the possibility of having moving pictures. In a 

 word, moving pictures are possible because we can see instantly, 

 but we cannot stop seeing instantly. 



To give views rapidly with proper illumination, involved the 

 discovery of means for artificial light of great brilliancy, and of a 

 machine by which the views could be lighted and moved along; 

 and finally the long series of discoveries and inventions in optics 

 and chemistry before photography was invented to make the pro- 

 duction of the views cheap and accurate. It was another long step 

 taken by Newton when he showed that white light in nature is 

 composed of the rainbow colors. Furthermore, it was shown by 

 him and contemporary and later physicists and physiologists that a 

 mixture of less than the seven colors of the rainbow gave to the eye 

 the appearance of white light. Even two complementary colors 



