Popular Science Monthly 



717 



of taking observations is to hoist an 

 officer to the top of an extension or 

 telescopic mast or tower. There the 

 view is excellent until a bullet or shell 

 interrupts his work. 



If in place of a human observer, the 

 "eye" or semi-spherical mirror of the ob- 

 servation apparatus were substituted the 

 securing of necessary observations would 

 not be as costly to life, and the view ob- 

 tained would be a 



more extensive one. 



More Motion - 

 Pictures in Color 



NATURAL- 

 color moving- 

 pictures have so far 

 achieved very little 

 success, mechanic- 

 al difficulties being 

 thestumblingblock 

 which no inventors 

 have yet been able 

 to overcome suc- 

 cessfully. One com- 

 pany has developed 

 hand-tinting to a 

 fairly satisfactory 

 degree, although 

 the results have not 

 yet attained the 

 necessary stand- 

 ard. The color ef- 

 fects are somewhat 

 obvious. Another 

 maker of colored 

 moving- pictures 

 placed his on the 

 market before be- 

 ing commercially 

 perfected. With 

 this process it was 



necessary to run the film through the 

 projecting machine at twice the normal 

 speed, natural-color results being ob- 

 tained by a revolving color disk which 

 allowed red and green pictures to be 

 flashed alternately on the screen. The 

 same process took place when the picture 

 was taken. The latest attempts at 

 moving-picture color photography is 

 suggested by an English inventor who 

 proposes to expose alternate "frames" 

 or pictures of a film through a shutter 

 provided with a color filter. On one 

 "frame" the colors in the photographed 



object which contain green will be regis- 

 tered on the next "frame;" various 

 shades and tones of red will be separated 

 out. When the positive film is printed 

 from the negative strip it will be stained 

 orange and green in alternation. Two 

 positive films will be printed from the 

 one negative and stained, then super- 

 posed and cemented together. Alternate 

 frames are stained green and orange, 

 and the two strips 



The observer sits safely inside the hut and 

 watches what is going on in the semi- 

 spherical mirror on the table 



SO arranged in as- 

 sembling that when 

 the film is ready for 

 projection one 

 green frame will 

 be opposite an or- 

 ange frame. The 

 film will be run 

 through the pro- 

 jection machine at 

 normal speed, i. e., 

 sixteen frames a 

 second, and the re- 

 sultant image on 

 the screen, if the 

 process works out 

 as it is planned, 

 will be lifelike in 

 color. By a com- 

 plication of the pro- 

 cess, using three 

 fundamental col- 

 ors, instead of or- 

 ange and green, fin- 

 er gradations of 

 color will be possi- 

 ble. The difficul- 

 tues which beset 

 this plan can be 

 removed by ade- 

 quate mechanical 

 means. Coloring 

 alternate frames red and green has not 

 yet been successfully accomplished — at 

 least on a commercial scale — although it 

 probably could be done. The other 

 difficulty is to secure positive film half 

 the present thickness which would be 

 sufficiently flexible and durable when two 

 strips were cemented. The matter of 

 superposing two film sections, so that 

 the images exactly coincide- — and this is 

 absolutely necessary due to the immense 

 magnification which takes place — is an 

 important mechanical problem which 

 must be thoroughly worked out. 



