Diving Bells and Suits 359 



tuses and come to the mention of physiological phenomena, not 

 much considered, as we shall see, by the celebrated engineer. 



An interesting fact appears at once; M. Triger wished to try 

 upon himself the effect of compressed air. Now: 



At the moment when the manometer had hardly risen to the 

 height of 40 inches (total pressure), there was a report, and we were 

 struck with icy cold and plunged into the most complete darkness, 

 because of the instantaneous formation of a thick mist: a windowpane 

 of the apparatus had burst. 



This explosion had no other result that to cause us a great 

 surprise. 



M. Triger next mentions, ascribing them quite accurately to 

 their cause, the pains in the ears that accompany compression and 

 decompression. Then he adds, and this is all his Memoir contains 

 on the subject which interests us: 



At the pressure of three atmospheres, it is not possible to whistle 

 in compressed air: but the power is lost only when one reaches this 

 pressure. 



In compressed air, everyone talks through his nose, and this 

 becomes increasingly noticeable with increase in pressure. 



The workmen have noticed that while they were climbing the 

 ladders, they were less out of breath in compressed air than in free air. 



I shall end with a rather interesting observation, which I was in 

 a position to note personally: namely, that a miner, named Floe, who 

 had been deaf since the siege of Antwerp, invariably heard more 

 distinctly in compressed air than any of his comrades. (P. 892.) 



Professor Trouessart, 7 commissioned by the Industrial Society 

 of Angers to investigate the practical results of the apparatus of 

 M. Triger, gave an account of his researches in an interesting 

 Memoir. 



There is very little mention of physiology in it; however, we 

 do find in it a few observations which deserve to be reported here, 

 particularly because they were the first made on man at pressures 

 of 3 atmospheres above the normal atmosphere: 



It is with a certain apprehension, we admit, that one goes down 



for the first time into the apparatus to be subjected to a pressure 



of three atmospheres there. These 32,000 kilograms above the former 



pressure which you will have to endure are enough to terrify the 

 stoutest shoulders. 



First comes the description of the pains in the ears, which are 

 thoroughly studied and explained: 



A phenomenon which is more difficult to understand is that deaf 

 persons not only hear better in compressed air than in free air, but 

 that they hear better than persons whose ears are normal .... 



