NAVIGATING THE AIR 



tions of such flying-machines; and it was but natural, 

 under the circumstances, that as soon as peace was 

 restored, efforts should be made there to produce a dirigi- 

 ble balloon, or some other form of dirigible flying- 

 machine. Giffard, as we have seen, had been fairly 

 successful; and now M. Dupuy de Lome, chief naval 

 constructor of France, took up the problem. He con- 

 structed a balloon with a cigar-shaped envelope one 

 hundred and twenty feet long and fifty feet in diameter. 

 Beneath this was a rudder placed in the same position 

 as that of a ship ; and suspended still further below was 

 a large car fitted with a two-bladed screw-propeller, 

 thirty feet in diameter. Manual labor was to be used 

 for turning this screw, two relays of four men each re- 

 lieving each other at the work. An ascent was made in 

 February, 1872, with fourteen persons in the car, who, 

 by working in relays, demonstrated that a speed of about 

 seven miles an hour could be maintained in any direc- 

 tion in still air. As the wind was blowing about thirty 

 miles an hour at the time, however, the course of the 

 balloon could only be deflected, and the main object of 

 the ascent — the return to Paris — could not be accom- 

 plished. In short, De Lome's balloon demonstrated 

 little more than had been accomplished by Giffard with 

 his steam-driven balloon. Both had shown that with 

 suflScient power the balloon could be made to travel in 

 any direction in still air, but neither had been able to 

 make headway against a strong wind. 



It was estimated at the time of Dupuy de Lome's 

 ascent, that had a steam-engine of a weight correspond- 

 ing to that of the eight workmen been used, at least 



[263I 



