speed proper to the submarine, would have been very inefficient ; our 

 two screws were enough for its steering. 



DIFFERENT TYPES OF BATHYSCAPHE 



We now knew how we could carry out the different operations in 

 diving, in rising again or in low-speed navigation at the bottom of the 

 sea. 



But how were we to get the bathyscaphe to the diving-place ? 



Several ways are possible.' 



The first consists in loading the bathyscaphe on a cargo-ship of large 

 tonnage and transporting it to the place : this was the method used for 

 the FNRS 2. From the hold of the cargo-ship itself the passengers 

 went into the watertight cabin : the hatch was then closed upon them : 

 then a crane lifted the submarine and deposited it upon the water. The 

 dive could begin. 



But this has one disadvantage : the weight of the submarine and 

 of the float filled with petrol. Hence a very large ship was needed, for 

 it alone would possess the hoisting installations necessary. But even 

 such a ship as this would list dangerously while it held the bathyscaphe 

 above the water and to counteract this tendency one would have to 

 shift some other cargo in the ship to trim her. This in its turn would 

 present other difficulties. A 'kangaroo' boat would have avoided all 

 these difficulties : but we did not have one at our disposal. 



As we could not choose the type of ship to carry us, we had to adapt 

 the weight of the bathyscaphe to the tonnage of the cargo ship. Thus 

 we were led to the idea of launching the submarine before filling the 

 float with petrol and then pumping the petrol in, with the pilot and 

 the observer already shut into the sphere. Once the dive was over 

 the reverse operation had to be done : that is, empty the float of its 

 petrol, then hoist the submarine on board : then only could the crew 

 leave the cabin. 



This was what we did with the FNRS 2 in the Cape Verde Islands 

 in 1948; we shall see that it was only possible in a very calm sea and 

 that the crew was obliged to remain shut up in the cabin for too long. 



The second solution seemed easier: fill the float at the home port 

 and from there tow the bathyscaphe to the diving-place. It is there that 

 the crew enters the cabin. 



But this meant that the float had to be strong enough to stand up to 

 towing, whatever the sea was like. Moreover, the shaft which per- 



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