WORK UNDER PRESSURE AND IN GREAT HEAT 391 



A number of experiments in the steel chamber at pressures 

 up to 6^ atmospheres were carried out on men, with stage decom- 

 pression ; and many dives in the sea to pressures of from 4 to 



Time in minutes. 

 Fig. 2. — Diving to 28 fathoms by old method. The thick line represents the air-pressure. 

 The curves, from above downwards, represent respectively the variations in saturation 

 of parts which half saturate in 5, 10, 20, 40, and 75 minutes. 



7J atmospheres have also been made by Lieutenant Damant 

 and others, with the time-limits and stage decompression recom- 

 mended in the new diving tables. No S3'mptom of caisson 

 disease has, however, been observed, so that the new method 



Time in minutes. 

 Fig. 3. — Diving to 28 fathoms by new method. The curves, from above downward, represent 

 respectively the variations in saturation of parts of the body which half saturate in 5, 10,^ 

 20, 40, and 75 minutes. The thick line represents the air-pressure. Diver 14 minutes 

 on the bottom and 46 minutes under water. 



appears to be practically successful. The old method was to 

 go down and come up slowly at a rate of about 5 ft., or 

 i^ metres per minute. The accompanying diagrams show the 



