SECT. 5] DEEP SUBMEKSIBLES FOR OCEANOGRAPHIC RESEARCH 499 



Galeazzi diving chamber and the Japanese Kuroshio are exceptions. Beebe 

 predicted the day would soon arrive when there would be scores of bathy- 

 spheres. But, to date, the only direct lineal descendent has been Barton's 

 benthoscope. In it he briefly dived off California in 1948 attaining a maximum 

 depth of 4500 ft. 



The bathysphere used in the early thirties was a 54-in. i.d. steel sphere 

 weighing 2.5 tons in air. Roughly 30 dives were made off Bermuda to a maxi- 

 mum depth of 3028 ft. Details of the scientific results and of the bathysphere's 

 construction are recorded in Beebe's (1935) book, Half -Mile Down. Beebe 

 reported a plethora of fishes and other sea life far in excess of that seen by any 

 subsequent observers ; unfortunately no photographic confirmation of his 

 observations was obtained. Access to the sphere for two observers was made 

 through a heavy steel door ; a view of the sea through two ports of fused quartz. 

 The sphere was lowered by a 1-in. wire rope and a power cable supplied lighting 

 and telephone communication. Watertight integrity proved troublesome ; leaks 

 through the door, the cable lead-through and the windows occurred from time 

 to time but without serious results. 



More recently, the Japanese constructed the diving chamber Kuroshio to 

 explore the waters around Japan for oceanographic and fishery research 

 (Fig. 2). Using the Oshoro Maru as the mother-ship, the Kuroshio completed 

 380 dives to a maximum depth of 205 m between 1951 and 1957. Inoue (1959) 

 mentions 21 papers which indicate the wide variety of studies made. These 

 researches emphasize especially fish behavior, plankton ecology, biolumines- 

 cence and the operation of fish nets, trawls and various types of traps. Studies 

 of light penetration, sea-floor geology and suspended matter were also 

 accomplished. 



As demonstrated to the writer in a descent to 120 m off Ito not far from 

 Tokyo in 1953, the standard technique is to lower the chamber to within about 

 3 m off the bottom. The chamber is then permitted to drift along with the 

 surface ship ; constant height over the bottom is maintained through telephonic 

 communications. The sea floor is well illuminated with several floodlights; 

 minute animals of the mid-water, even as small as copepods, could be observed 

 by looking directly down a strong beam of light. 



In 1959, plans were under consideration for reconstructing the Kuroshio 

 into a tethered submarine craft which would cruise within the limits of an 

 "umbilical cord" supplying propulsion power from a small mother ship. 

 Returning to the surface, the craft would be towed rather than hoisted aboard. 

 Some of the basic specifications proposed were : height 3 m, length 7 m, dia- 

 meter of cylindrical chamber 1.48 m, length of manned cylinder 5 m, gross 

 weight 9 tons, diving depth 200 m, complement 4 persons, endurance 10 hours, 

 cable diameter 30 mm, underwater velocity 2.5 knots, 10 windows, 3 peep- 

 holes and 7 floodlights. There would also be various communications equipment 

 for sounding devices, scientific apparatus, etc. If ever realized, this craft will 

 be a novel and interesting addition to the world fleet of underwater research 

 vehicles. 



