earth's crust which is covered by the sea. Up till now the only means at 

 our disposal had been those installed on board a Dutch submarine by 

 Professor Vening Meiners: for this the submarine had to remain 

 stationary for hours at a constant depth, the members of the crew 

 being condemned to absolute immobility. The data would be at once 

 more exact and easier to obtain if the gravimetric pendulum were 

 placed in the cabin of our bathyscaphe, stationary as it is in the mud. 

 One would still have to study the problem of the transmission of hourly 

 signals by ultrasonic methods. But the difficulties are not so great that a 

 solution cannot be found. 



UP TO THE SUNLIGHT 



At the end of a quarter of an hour, thinking it useless to prolong our 

 sojourn at the bottom, we decided to go up. The machine had to be 

 lightened. The opening of one of the ballast tanks was blocked up by a 

 plug : the other was free and allowed four tons of iron pellets to be 

 thrown overboard, that is to say, more than is necessary to compensate 

 the overload that we had on touching bottom and to drag the cabin 

 out of the mud. Jacques turned the switch, and in theory the ballast 

 should have flowed away, but it was impossible in this mud to make 

 sure of it. The silence was total, a real silence of the tomb. However, 

 the situation was in no way alarming: a single tank was available; 

 the iron pellets thus could not flow out faster than a rate of no lb. a 

 minute. And even after this tank was emptied, we could still throw the 

 other overboard, in other words, 8800 lb. of supplementary iron pellets 

 and 4400 lb. more, the weight of two ballast tanks when empty. Sud- 

 denly the bathyscaphe leant forward and the mud ran along before the 

 porthole. I rushed to it in the hope of perceiving the bottom at last. 

 But, in dragging itself out of the mud, the cabin stirred it up ; a cloud 

 formed and, when it had cleared away, the bottom was already out of 

 sight. 



The dive entered upon its last phase : as we did not open the control 

 valve and as, following upon the decrease in pressure, the petrol 

 expanded, the bathyscape became more buoyant and the speed of its 

 ascent increased : it reached about 3-3 ft. a second. In the glimmer of the 

 projector innumerable dots of light showed themselves : the particles 

 of mud stuck to the cabin were loosened and were outlined pale against 

 the black background. During the greater part of the ascent we turned 

 out the projectors: the phosphorescent animals interested me more 



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