set up would not be beaten for many years. In my reply I had to 

 contradict him. 



*It will be a fine day for me,' I said, 'when other stratospheric 

 balloons follow me and reach altitudes greater than mine. My aim is 

 not to beat and above all not to maintain records, but to open a new 

 domain to scientific research and to aerial navigation.' 



In the months that followed, although we reached the altitude we 

 aimed at, our enterprise was called foolhardy, partly because the 

 valve rope became jammed : if we are safe and sound, it appears, it is 

 a miracle. My spherical balloon had a bad press : I had no emulator, at 

 least at the beginning. Meanwhile I kept myself occupied with work 

 on cosmic rays. After a while I wanted to make a new ascent. This time 

 it was my friends of the Aero- Club of Zurich and more especially 

 Dr. E. Tilgenkamp, Colonel Garber and Dr. Bonomo who took it 

 upon themselves to organize it. 



In the early days of August, the weather forecast seeming favourable 

 we decided to set forth the next day: the balloon was to be inflated 

 during the night. In the afternoon, in radiant weather, the envelope 

 arrived and was spread out. A little later, M. Jaumotte, director of the 

 Belgian Meteorological Institute, rang me up from Brussels. He had 

 heard that we were planning to take the air, but he warned me that 

 thunderstorms were expected over central Europe during the night. 

 Zurich confirmed this forecast, so I did not hesitate. Although the 

 crew was already mobilized and everything ready for the business of 

 filling the balloon, we cancelled the departure. 



I still remember what the reporters thought of it : for was not the 

 sky cloudless ? Fortunately I stuck to my decision. And I smiled when 

 later a violent storm burst over Zurich and Dubendorf. That night, I am 

 sure, meteorology gained prestige in the eyes of the international press. 



On the 17th August, finally, the forecast was good. In splendid 

 weather, in the night, without a breath of wind, the FNRS was in- 

 flated : on the 1 8th, before sunrise, all was trim and at seven minutes 

 past five in the morning, ' Let go ! ' rang out. What can I say about the 

 ascent.'^ Everything went smoothly according to our plan, like a 

 laboratory experiment prepared with minute care. We found out that 

 the particular gamma radiation, which according to a certain hypo- 

 thesis should have been manifest above in an intense fashion, did not 

 exist. Enjoying perfect visibility, we drifted slowly above the Lake 



[16] 



