ILLUSTRATIONS 



1 Mercury vapor lamp employed in the original lighting system, 

 on the bathyscaph. . . page 5 



2 Mercury vapor lamps of original lighting system shown 

 mounted in tandem as originally used on bathyscaph. . . 6 



3 General Electric AH-6 lamp that was unsuccessfully attempted 

 as a substitute for original mercury vapor lamp. . . 7 



4 Construction details of NEL deep submergence lamp. . .2 



5 Oblique view of assembled NEL deep submergence lamp. . . 22 



6 Top view of NEL lamp showing single mounting hole and 

 recessed Joy plug for +24 vdc connection. . . 12 



7 NEL lamp with bulb, bulb mount, and back removed. . J.3 



8 Same as figure 7 with Plexiglas window and heat shield 

 removed and showing recessed window mounting. . . 24 



9 NEL lamp casing, tested to destruction, showing the inside 

 surface of the window, inside of casing, and the bulb and bulb 

 mounting. . . 14 



10 Same lamp casing showing outside of the window, the front 

 of the casing, and the back of the mounting plate. . . 25 



11 Edgerton lamp with reflector removed. . . 26 



12 Edgerton lamp with reflector in place. . . 2 6 



13 Disassembled BUSHIPS lamp casing. . . 2 7 



14 Components of two BUSHIPS lamp casings after testing to 

 destruction. . . 18 



15 PEK Laboratories 500-watt, 24-vdc incandescent lamp, 

 Model No. 3. . . 2 9 



16 Side view of NEL lamp cluster under the bow of the bathy- 

 scaph. . .20 



17 Bottom view of bow lamp cluster. . . 20 



18 Two five -lamp clusters of NEL lamps, amidships. . . 20 



19 Edgerton lamp mounted on bathyscaph ballast tub for use 

 with closed-circuit TV. . . 20 



20 Photograph taken during Dive No. 8 3, 13 November 1961. . .22 



21 Photograph taken during Dive No. 83, 13 November 1961. . .22 



