than the illuminated particles of mud. A glance at the gauge was 

 sufficient to assure me that the ascent was continuing : it went on with- 

 out rolling, without jarring. 



A child's balloon goes up in zigzags. It is not the buffetings of the 

 wind that induce these changes in direction : if one repeats the experi- 

 ment in a large hall sheltered from all wind, the ascent will take place 

 in the same manner. It is the eddies produced by the balloon itself 

 which are the cause of its behaviour. One has only to give it a light 

 load, so as to decrease the speed, to establish that there is a critical 

 speed : below this speed, the trajectory is strictly vertical, and above it, 

 the eddies make the balloon zigzag. In the same way, if a tennis ball is 

 released at the bottom of a bathing pool, it ascends in a zigzag. If the 

 bathyscaphe rose too fast, it would behave in the same manner. It is 

 impossible to determine in advance by calculation the critical speed 

 beyond which the eddies would be formed: I had therefore made 

 provision for coping with too great oscillations by using a parachute : 

 attached beneath the cabin, it would open and would brake the ascent. 

 Once more this is an analogy between the aerostat and the bathyscaphe. 

 However, trusting to remain below the critical speed, I calculated that 

 we could do without it. My optimism was justified : more smoothly 

 than in the best of lifts we rose without the slightest oscillation.! 



We were still in darkness. But for the instruments we could still 

 have believed ourselves at the bottom. It is a thrilling moment when the 

 first gleams filter through the portholes ! Little by little the illumination 

 grows. From then on there were no more phosphorescent animals. 

 Soon it was light enough for us to recognize objects in the cabin, with 

 all the lights out. The daylight increased and the portholes were 

 resplendent with a bluish light. The cabin began to sway, a slight 

 rocking : we had reached the surface. Above us the rays of the sun 

 played in the waves : spots of light danced in the antechamber. Sud- 

 denly the ringing of the telephone made us jump. After forty-five 

 minutes there we were again in contact with the external world and its 



civilization. 



When the Trieste dived, the escort units moved out to avoid any 

 danger of collision. The pneumatic dinghy manned by Mr. Salvio and a 

 sailor alone remained in the neighbourhood. When the Trieste sur- 

 faced, 500 yards separated the dinghy from the bathyscaphe: rowing, 

 the two men tried to race the Tenace to the scene and the Tenace^ 

 1 This was not always to be the case (see page 134). 



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