WONDERS OF THE DEEP 43 



but when it is taken into consideration that it had 

 been perfected only after years of study and experi- 

 ment, often hampered by difficulties that would have 

 discouraged many, one may get a fair idea of what 

 it meant to the inventor when he discovered that 

 his invention was practical. It had been tested before 

 it was taken to Nassau, but the supreme test of the 

 tube, the chamber, and all the other paraphernalia, 

 came when they took it to strange waters, with the 

 currents of which they were altogether unfamiliar. 



It took three or four days for the party to prepare 

 everything for the submarine trip. The first thing 

 that had to be done was to place the observation 

 chamber in position in the shaft, and this was a rather 

 slow process, as the chamber is heavy, and has to 

 be lifted with big steel cranes. Next came the fitting 

 of the heavy glass. This is in one piece, and had to 

 be handled very carefully indeed while it was being 

 fitted to the window. When it was in position, a 

 heavy iron band had to be adjusted over its edge and 

 fastened to the steel grooves on the rim of the 

 chamber, so as to make it absolutely waterproof. 



Then came the fitting of the tube, which is made 

 in sections, and is securely fastened together in cork- 

 screw fashion. When everything was in place, one of 

 the members of the expedition went down the tube 

 and saw that all was in readiness in the operating 

 chamber for the camera man and the observer. The 

 camera was next placed in position, and the operator 

 and his companion descended the tube, one at a time, 

 with ropes fastened round their waists to guide their 



