Upon removal from the pressure tank, the bulb was found 

 to be intact, but a small amount of fluid had passed into it. 

 The second test bulb (fig. 15) sustained damage that pre- 

 cluded operating tests, but a series of structural tests of 

 the bulb were conducted and the envelope was found to leak 

 at 16, 000 psi. 



Figure 15. PEK Laboratories 500-watt, 24-vdc 

 incandescent lamp, Model No. 3. 



RESULTS AND DISCUSSION 



By using a combination of the NEL lamp with its reliability, 

 long life, and ease of replacement, and the Edgerton lamps 

 with their satisfactory areal lighting, some fairly good 

 results, both visually and photographically, have been 

 obtained. Figures 16 through 19 show the various mountings 

 of these lamps on the bathyscaph. 



It will be necessary to continue the lighting development 

 program until lights are developed that provide the proper 

 color temperature to produce the best possible photographic 

 results. After over a year of effort, it is believed that this 

 program is entirely feasible; however, a great deal of 

 further effort will be necessary before the objectives are 

 attained. 



It is expected that supplementary reports will be issued as 

 further results are obtained during the course of the program. 



19 



