a door which he closed behind him: only after this did he open a 

 second door which gave him access to the outside : at no time were the 

 two doors open at once and the beast had not been able to get out. 

 Forty years later I had not forgotten this scene. The tamer was now 

 the ballast, which had to get out of the cabin without allowing the lion, 

 that is, the air, to follow it. 



It was sufficient to apply the principle of the air-chamber : let there 

 be a container provided with two straight-through taps. By means of 

 a funnel, we pour the ballast into the container through the upper 

 cock, the ballast being composed, in our case, of lead-shot. Then, 

 after this cock is closed, the lower cock is opened and through it the 

 ballast pours directly towards the outside. So that the lead-shot in 

 falling might not injure spectators, a very fine shot is needed. I made 

 sure myself that there was no danger, by standing at the bottom of the 

 big chimney of the University of Brussels under a rain of shot which 

 was poured on my head from a height of 165 ft. 



All would have been for the best if international regulations had 

 permitted anything other than sand or water for ballast. What was to 

 be done ? To cut all discussion short, I declared that I had as ballast 

 lead-sand. This explanation aroused no objection. However, by 

 definition, sand is a non-metallic substance and nobody has ever seen 

 lead-sand ! I thus imitated the famous priest in the anecdote who was 

 served with roast chicken on a Friday : he baptized it ' carp ' and was 

 thus able to enjoy it with a quiet conscience. 



Let us note in passing that it was iron-shot which was used as 

 ballast for the three bathyscaphes. 



My brother, for his balloon, has found a graceful method of resolving 

 the problem and satisfying the regulations in force: this time the 

 ballast is of sand, real sand, and the sacks which contain it are arranged 

 on the outside of the cabin : each one of them contains a detonator 

 which electric conductors connect with a battery lodged in the cabin. 

 A simple pressure on the switch button suffices : the sack rips open and 

 empties itself. Afterwards this arrangement was adopted on the 

 Explorer 11^ with which the American pilots reached i3f miles. The 

 balloon had been inflated in a sheltered valley : the balloon commenced 

 its ascent when, suddenly, the wind beat it down upon trees standing 

 on a ridge. If the pilot had not immediately made use of his switch- 

 board the Explorer II would have been destroyed. No other system 

 of unballasting would have been speedy enough to save the balloon. 



[7] 



