534 SCIEXCE PROGRESS. 



when the French discovered that he was an Austrian they 

 tore his machine to pieces — he himself only escaping after 

 a thrashing. 



The difficulty of controlling balloons has from the out- 

 set been recognised as the chief obstacle in the way of their 

 adoption as means of locomotion. In the Hist aire des 

 Ballons, M, Tissandier reproduces an amusing eighteenth 

 century cartoon published in France when ballooning was 

 at its height, representing a Mc^thodc infaillihlc dc diriger 

 les Ballons. The figure shows a balloon drawn along by 

 donkeys, the man on the balloon is suspended by his waist 

 and is blowing a horn and carrying a lantern to signal to 

 the donkey-drivers. 



In 1850 M. Petin designed a great air-ship, and actually 

 succeeded in raising over ^1000 for its construction. The 

 machine was to be supported by five balloons placed side 

 by side and driven by a gigantic screw propeller. One of 

 the weak points in his scheme was that Petin said very little 

 about the motive power. His figure, however, shows an 

 engine rather resembling a traction engine at one side of the 

 platform, which would be. one would think, rather a heavy 

 load for the balloons and likely to disturb the balance of the 

 machine. The machine was built, but before Petin could 

 make an ascent in France he quarrelled with certain officials, 

 and the Prefect refused to give him the necessary permission. 

 Accordingly he went over to England, and then to America, 

 where he had another machine constructed, and made pre- 

 parations to let it off at New Orleans. The machine was 

 all ready, but it was found that the gasworks were not equal 

 to the occasion, or. at any rate, this was Petin's excuse for 

 not going up. 



Since the time of Petin the problem of the navigable 

 balloon has been attacked more or less continuously, some- 

 times, but rarely, with partial success. Among the earlier 

 attempts, a kind of aerial machine was proposed by Lanson, 

 who made experiments with it, but the results were far 

 from conclusive. A system of steering a balloon, invented 

 by M. Helle, was never experimented with. Another 

 navigable balloon was constructed by M. Dupuy de Lome, 



