356 Historical 



Brize-Fradin, from whose work 3 I have borrowed most of the 

 preceding information, summarizes in the following words the 

 disadvantages of the diving bell: 



1. Keen and unendurable pain in the ear, due to the compression 

 of the tympanic membrane; 



2. Deterioration of the air by the breathing of the workmen, with 

 asphyxia as the result; 



3. Most physicists have found a third disadvantage; they believe 

 that the elasticity of the air, acting in all directions and at all depths, 

 compresses the blood vessels, and the arteries, and causes hemorrhages. 



We may oppose to this statement unvarying data and direct 

 experiments; let us listen to M. Halley: 



"I myself was one of the five persons who dived to the depth of 

 18 meters, without being inconvenienced by it; we remained for an 

 hour and a half; I could even have staid there longer, for there was 

 nothing to prevent it." 



This testimony of M. Halley could be seconded by that of all the 

 divers. The pressure of the air under water, at a depth of 18 meters, 

 does not cause blood-spitting; if one dived deeper, of course, he would 

 find the limit where the compressed air could not be breathed. (P. 171) 



And yet, adds Brize-Fradin: 



Noting the equal value of the water pressure and the compression 

 of the air, it seems that the diver placed under the bell at a depth of 

 18 meters should be in a state of general collapse. (P. 173) 



The Court Councilor of the Emperor of Russia, whose fatal 

 ascent of Mont Blanc we have already reported, Dr. Hamel, 4 

 descended in a diving bell installed by Rennie in the port of 

 Howth, near Dublin; the depth of the water was about 30 feet. 

 He felt no other inconvenience than violent pains in his ears, "as 

 if some one were forcibly inserting a stick," which he checked 

 by swallowing his saliva. From that the idea came to Hamel "that 

 the divers' bell might serve as a remedy in cases of deafness 

 resulting from the obstruction of the Eustachian tube." 



In regard to the rest he merely says: 



I expected to experience some painful effect upon respiration, 

 resulting from the pressure of the air increased by the weight of 

 almost a whole atmosphere; and yet I did not feel the least incon- 

 venience in this respect. 



The same year, Dr. Colladon B descended in the same bell and 

 to the same depth. He is a little more explicit: 



We descended so silently that we did not perceive any movement 

 of the bell; but as soon as it was immersed in the water, we felt in 

 our ears and on our foreheads a sensation of pressure which kept 



