differences were in the plastic pressure barrier, the 

 types of wires, and the fabrication method. Tests were 

 made to find an epoxy bonding agent more satisfactory than 

 the material formerly used. The older material had a 

 tendency to crack internally after a period of time, and 

 tended to pull away from the metal sides of the hull con- 

 nector creating a possible water leakage path. To compen- 

 sate for this fault, M. Piccard put a layer of synthetic 

 beeswax on top of the epoxy casting, so that if any cracking 

 or pulling away occurred, the beeswax would flow into the 

 resultant gap and seal it. It was considered, however, 

 that the primary epoxy barrier itself should withstand full 

 pressure without developing any leakage paths. The search 

 for suitable materials and improved fabrication methods 

 was time consuming; however, eventually, a hull connector 

 system was developed using improved epoxy that was 

 capable of withstanding over 16, 000 psi for a period of 

 24 hours without developing any leakage. After each of the 

 connectors had passed this test, the synthetic beeswax 

 material was poured on top of the epoxy as a further safe- 

 guard. 



An additional hull connector was acquired for use as 

 a wire passage. Formerly, this connector had been used 

 as a passage for a single blow line for the antechamber. 

 By converting to the electrically operated blow system 

 located external to the sphere, this connector, instead of 

 carrying one piece of high-pressure tubing, was used for 

 one heavy duty copper buss that provides 24-volt power to 

 the inside of the sphere from the external battery boxes. 



14. FATHOMETER 



The first Fathometer was capable of giving height in- 

 formation only for some 40 fathoms above the bottom. In 

 the same sized package, the new Fathometer gives a 2 00 

 fathom trace, thus providing the pilot with earlier warning 

 of the approach of the bottom. In addition, the Fathometer 

 transducer was modified to make the beamwidth slightly 

 smaller so that the representation of the bottom beneath 

 would be more accurate. 



40 



