76 



Overton \m> Harper, />'/>•</ Photography, 



l.lan. 



although some experience and skill are required to secure the best 

 results. The factorial method oi controlled-time development, 

 as described in tin" directions accompanying the plates, enables one 

 to control the density and contrasl oi the picture. The image 

 formed by thefirst development of the plate is reversed in a reduc- 

 ing solution, and the plate is thereby converted from a negative 

 into a positive. The (irsl development, reversal of the image, 



second development, and washing-, may be completed in less than 



fifteen minutes, and the thin emulsion may l>o dried in ten minutes 

 more. An autochrome, therefore, possesses a still further advan- 

 tage over a hand-colored slide in the much shorter time required 

 for its completion, 



\n autochrome plate is a positive, and no satisfactory method 

 has yet been devised for making colored prints from it directly 

 upon photographic paper. It is Well within the hounds of proba- 

 bility, however, thai experiments which are now being conducted 

 in this direction may eventually be successful. Fortunately, any 

 number oi duplicates may be made by photographing the first plate 

 upon other autochrome plates, in much the same way that lantern 

 slides arc made by the use of a camera. 'The reproduced auto- 

 chromes arc not so brilliant as the originals, hut they may he shown 

 w ith good effect in a lantern. 



We have taken several dozen bird authochromes that may he 

 considered successful. The list includes the Laughing Gull, Com- 

 mon Tern. Black Skimmer. Bob-white, Fish Hawk. Flicker, Night- 

 hawk. Blue Jay, Song Sparrow. Purple Martin. Yellow Warbler, 

 Catbird, Brow n Thrasher, and Robin. The number oi our failures 



to secure good pictures has not exceeded the number of our successes. 



Our experience justifies us in stating that the autochrome method 

 oi photography affords a practical and definite means of securing 

 brilliant and useful photographs oi normal wild birds in their 

 natural haunts, poses, and colors. 



