This change was made primarily because of the ease with 

 which aluminum can be machined. There was also the 

 probable necessity for SCUBA divers to change the" lamps 

 under water. The much lighter aluminum construction 

 would permit ease of replacement by such divers. 



PLEXIGLAS RETAINING RING 

 PLEXIGLAS 

 HEAT GLASS 

 PYREX WINDOW 



RETAINING SPRINGS 



POSITIONING SPRING 



FILLER HOLE FOR 

 WATER CHAMBER 



O-RING GROOVE 



CAP HOUSING 



Figure 4. Construction details of NEL deep submergence 

 lamp. 



10 



