Diving Bells and Suits 361 



wine soon relieved this pain in both men; they kept on working the 

 following days. 



In 1846, M. de la Gournerie, 9 getting his idea, he said, from an 

 apparatus suggested in 1778 and approved by the Academy of 

 Sciences in 1779, used for the extraction of rocks in the channel 

 of the port of Croisic a boat with a metal chamber open at the 

 bottom, from which the water was expelled by compressed air. 



He submerged it only 3 or 4 meters; it is not surprising then 

 that 



The workmen never found that the air pressure inconvenienced 



them. It merely gave them a slight discomfort in the ears for a few 



seconds. 



The pulse rate is not noticeably increased. (P. 308.) 



In the mines of Douchy (Nord) the method used by M. Triger 

 on the banks of the Loire was first imitated. The difficulties were 

 greater, because here it was not a matter of penetrating permeable 

 sands with a sheet-iron tube 1.50 meters in diameter, but of 

 digging a shaft 3 meters in diameter through limestone. 



We shall shortly quote the important Memoir which the physi- 

 cians Pol and Watelle devoted to the study of the symptoms which 

 attacked numerous workmen in this undertaking. The first ac- 

 count of them was given by a report of the engineer Blavier, 10 

 sent to examine this new invention. 



He first mentions the pains in the ears and the inability to 

 whistle. A certain effort must be made in speaking: 



It seemed to us also that in the diatonic scale the voice lost a tone 

 or a tone and a half in the upper notes without gaining in the lower 

 ones. 



He found no difference in the pulse rate before entering the 

 apparatus and while within it: 



If the effects of compressed air upon the animal organism do not 

 appear during the whole time that one is subjected to it, at least 

 during one shift of workmen, the same thing is not quite true if we 

 try to consider subsequent effects .... Most of the workmen, although 

 selected from the most robust and healthy, have frequently felt 

 heaviness in the head or pains in the legs a few hours after leaving 

 the caisson. Only one of them experienced complete paralysis of 

 arms and legs for 12 hours. The superintendent of the mine assured 

 us that the effects felt almost always coincided with some excess 

 committed between shifts. (P. 361.) 



However, Blavier himself, after being subjected to the total 

 pressure of 2.6 to 3 atmospheres, was attacked by a fairly severe 

 symptom: 



