Figure 10. Same lamp casing showing outside of the 

 window, the front of the casing, and the back of the 

 mounting plate. 



EDGERTON LAMP 



During the course of the investigation and development just 

 described, Dr. Harold E. Edgerton of Edgerton, Germes- 

 hausen, and Grier was contacted and indicated that he could 

 construct a lamp that would be suitable for use with the 

 bathyscaph. An order for six lamps was placed with Edgerton, 

 Germeshausen, and Grier. The delivery time, however, was 

 not favorable, and the indicated life of these lamps was short 

 compared to that desired. 



The Edgerton lamp (fig. 11 and 12) utilizes a pyrex casing 

 in a tubular form. Mounted inside the tubular casing in an 

 inverted position is a 300-watt projection lamp. Whereas 

 this lamp was designed to burn at 28 volts, the 24 volts 

 supplied by the bathyscaph power supply causes the lamp 

 filament to burn brightly enough to furnish adequate illum- 

 ination for visual observations and photography providing a 

 high-speed film is used. The 300-watt projection bulbs 

 designed for 24v dc have been ordered. It is expected that 

 this will improve the lamp somewhat although the bulb life 

 will probably be shorter. 



15 



