Burling — Photographing Fossils by Reflected Light. 99 



Art. XII. — Photographing Fossils by Reflected Light / by 

 Lancaster D. Burling. 



The successful photography of fossil organisms is riot easy, 

 and when the specimens have no relief and are hardly to be 

 distinguished, except by Teflected light, from the rock on 

 which they rest, the problem becomes one of great difficulty. 

 Several thousand such specimens were collected by Dr. Chas. 

 D. Walcott in the Canadian Rockies, and Dr. R. S. Bassler, 

 Mr. J. M. Jessnp, and the writer have been working upon a 

 method of photographing them by reflected light. The 



Fig. 1. 





scheme developed seems to yield excellent results, is believed 

 to be new, and may be generally valuable in photographic 

 reproduction. 



The back of an ordinary enlarging and reducing camera was 

 pivoted so that it would revolve about a vertical line passing 

 through the center of the groundglass or plate, and the rack 

 upon which the specimens are mounted was made to revolve 

 about a vertical line passing through the center of the speci- 

 men. Suitable scales were so attached to both the specimen 

 rack and the back of the camera that each might be clamped 

 at any desired angle. In practice the specimen is placed in 

 position, the lens is removed, and the relative position of the 

 light and the angular position of the specimen are manipulated 

 to secure the most favorable illumination.* In order to elimi- 



* Experience has shown that variations in the intensity of the reflected 

 light are necessary to bring out the particular features of different speci- 

 mens and that the degree of illumination required can best be determined 

 by direct observation through the camera, rather than upon the groundglass. 



