on the inside of the rings, the crevice between the ring and the spherical 

 surface of the cabin was packed with lead. As it turned out, the joint 

 never leaked. 



Fig. io. The Trieste. Joining the two hemispheres of the cabin 



OPENINGS FOR CABLES AND TUBES THROUGH THE WALL 



The passage of the cables and tubes through the wall of the cabin 

 raised difficult problems. A number of thin copper wires had to con- 

 duct the electric current to various instruments placed outside the 

 cabin: magnetic valve and electro-magnet for the ballast; telephone, 

 radio, tachometers and some small electric bulbs. The projectors, the 

 motors and, as originally planned, the accumulators required con- 

 ductors of rather large cross-section. Furthermore, a tube was needed 

 to connect the pressure gauge with the external water-pressure; and 

 another for the compressed air which was to drive the water out of the 

 entrance shaft. Last, two schnorkel tubes, with cross-section sufficiently 

 large to provide ventilation for the cabin when the bathyscaphe was 

 on the surface. These openings had to comply with two conditions. 

 First, the pressure had in no case to be able to drive the conduit 



[90] 



