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POPULAR SCIENCE MONTHLY. 



ated air within expelled. On the deck are also a derrick and a power- 

 ful sand pump for use in wrecking or in Submarine construction, while 

 a powerful electric lamp in her conical under-water how illuminates 

 the field of her operations. Most interesting is the sea door at the bot- 

 tom forward, through which divers enter and leave the boat when on 

 the ocean floor, the inrush of water into the diving compartment being 

 prevented in the meantime by air pressure within, equal to and balanc- 

 ing the water pressure without. The 'Argonaut' has already traveled, 

 it is said, hundreds of miles on the surface and scores on the ocean 



Fig. 9 1 ross Section of the 'Argonaut' Amidships. 



bottom. She can remain at the bottom as long as her gasoline and 

 provisions hold out, with no other inconvenience to her crew than is 

 occasioned by the somewhat restricted room within. 



Mastery is the motto of mankind. Instinctively the race is ever 

 obedient to that ringing commission of the Omnipotent: "Replenish 

 the earth, and subdue it — and have dominion." Man longs to explore 

 every unknown realm. He thirsts for knowledge, which is power, and 

 by it he masters the mighty forces of nature and makes them his ser- 

 vants. It seems a little thing to have dominion over the habitable por- 



