THE IMPENETRABLE SEA 



his dives were successful. He used a leather suit with a 

 copper helmet, and the air supply — from. a small reser- 

 voir connected to the helmet — was water-cooled and 

 circulated back to the diver. With this apparatus divers 

 were able to stay under water for short periods, but if we 

 dismiss accounts of Borelli's and Lethbridge's inventions 

 as inadequately substantiated (and some of the accounts 

 credit Borelli with the perfection of a boat that could be 

 rowed under water!) the diving-suit was still not per- 

 fected. 



Kleingert of Breslau, in 1 798, incorporated much of 

 the experience of his predecessors in the completion of 

 what might well be regarded as the first practical and 

 self-contained breathing mechanism. The diver was 

 weighted for his descent, and released his weights when 

 he wanted to rise, being hauled to the surface as he held 

 on to a rope. Two pipes from above the surface gave him 

 fresh air and carried away the foul air from his lungs. 

 His apparatus was repeatedly used for depths up to 

 twenty feet. 



William H. James is sometimes credited with having 

 invented the first self-contained diving-suit supplied with 

 compressed air, in 1825. ^^^ Augustus Siebe, intro- 

 ducing his first diving-suit six years earlier, forestalled 

 him, and James's invention was never tested. Siebe's 

 first diving-suit was the ''open" one in which the air 

 escaped from under the diver's tunic around his waist, 

 but he modified his original suit in 1837, by making it the 

 now familiar ''closed" dress of deep-sea divers, with air 

 pumped under pressure from the surface. In 1878, H. A. 

 Fleuss, in association with Siebe, Gorman and Company, 

 brought the diving-suit to a state of perfection that has 

 ensured its use ever since. 



As first introduced it provided a continuous supply of 

 oxygen from the helmet, where it was stored in a com- 

 pressed state, the supply being regulated by the diver. 

 The carbonic acid exhaled was absorbed by caustic soda. 



174 



