330 



SCIENCE 



[Vol. IV., No. 



quickly comprehend the diversity of usage proceeding 

 from the same stock. 



— The new steering apparatus for balloons invented 

 by the two French officers of engineers, Capt. Renard 

 and Capt. Krebs, is attracting considerable attention 

 in warlike Europe. The experiments, for which 

 Gambetta during his short lease of power obtained 

 a grant of 100,000 francs, have been conducted for six 

 years past in the forest of Meudon with the greatest 

 secrecy. The two officers have admittedly been 

 guided in their studies by the earlier labors of Mr. 

 Duprey de Lome in 1870-72. The conditions laid 



four hours. Of their first trip, the inventors made 

 the following report : — 



" On Aug. 9, at four p.m., with the wind almost 

 calm, the aerostat, with little ascensional power, rose 

 slowly to the height of the surrounding uplands. 

 The machine was put in motion; and soon the aero- 

 stat increased its speed, obeying the slightest move- 

 ment of its rudder. The route was first held north 

 and south, toward Chatillon and Verrieres, above 

 the road from Choisy to Versailles; and, in order not 

 to become entangled among the trees, the direction 

 was changed to Versailles. Above Villacoublay, we 

 were about four kilometres from Chalais; and, per- 



down by the inventors -themselves were stability of 

 passage obtained by the cigar-shaped form of the bal- 

 loon and the arrangement of the rudder, diminution 

 of the resistance of the air by the choice of dimen- 

 sions, and realization of a speed capable of resist- 

 ing the winds generally prevalent in France. Capt. 

 Renard undertook the more strictly scientific part of 

 the work, and Capt. Krebs the rest. The former 

 invented the new electric pile of exceptional light- 

 ness and power; and the latter constructed the 

 screw and the rudder, and the apparatus for the 

 electric motor. The balloon is formed in the shape 

 of a cigar, pointed at both extremities; a net hangs 

 from it, containing seats for two aeronauts, a direct- 

 ing apparatus, and a rudder. It is stated that the 

 force is obtained by a series of electric accumulators 

 of ten horse-power, which may be operative during 



fectly satisfied with the behavior of the balloon, we 

 decided to return and to descend at Chalais, notwith- 

 standing the narrow space allowed by the trees. The 

 balloon was successfully turned to the right, the rud- 

 der making a small angle (about eleven degrees). 

 The diameter of the circle described was about three 

 hundred metres; the dome of the Invalides, taken 

 as the point of direction, was a little to the right of 

 Chalais. After arriving above this point, the bal- 

 loon was easily turned to the left; and soon it was 

 hovering three hundred metres above its point of 

 departure. It was necessary to work the machine 

 backward and forward, in order to bring the balloon 

 above-, the place chosen for the descent. At thirty 

 metres above the ground, a rope dropped from the 

 balloon was seized, and the aerostat was brought, 

 down in the very meadow whence it had set off.. 



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