SUMMARY AND CONCLUSIONS 333 



on deck, after two or three minutes of gradually escaping 

 air under pressure, the final blowout was less severe on our 

 ears than from a rapid descent to four fathoms in the 

 diving helmet. 



Careful records with a deep-sea pressure gauge in this 

 area give the usual mathematical ratio of increase, as 

 known for the deep sea in general. The pressures with- 

 stood by the bathysphere were as follows: 



Pounds per Tons on Each Total Tons 



Sqtuire Inch Window on Sphere 



2510 feet 1129.1 15-95 5822.3 



3028 feet 13^0.3 19.22 7016.3 



(d) Clarity of Observation 



The fused quartz windows and the remarkable clarity 

 of the deeper layers of the ocean combined to give unusual 

 clearness in our field of vision. The 1000 and 1500 watt 

 electric lights, from 1000 feet down, cut a brilliant swath 

 through the blackness. By accurate focusing with a num- 

 ber three, Zeiss binoculars, and then checking up the un- 

 changed focus on deck, I discovered that the limit of visiv- 

 bility in this beam, and hence of recognition of organisms, 

 was 45 feet away. Although the sides of the beam seemed 

 to become abruptly blackish blue, yet organisms passing 

 out of the direct glare reflected the light for many feet 

 above and below. Yet organic lights and flashes stood out in 

 strong contrast, even a few inches from the path of arti- 

 ficial light. 



