392 



Historical 



serious symptoms must have been the result, under certain circum- 

 stances, of forgetting this fundamental rule. 



It is scrupulously observed in the apparatus of MM. Rouquayrol 



Fig. 8— Diver equipped with the Denayrouze regulator, helmet removed. 



and Denayrouze. The diver dressed in their suit does not breathe 

 directly the air furnished him by the pump; on his back there 

 is a metal reservoir in which the compressed air is constantly 



