THE AVIATOR FLYING-MACHINE. 395 



names of all the known motors, and still less of the apparatuses 

 which might be applied as motors. Inventors reserve many sur- 

 prises in that matter. But, without letting imagination carry us 

 beyond the domain of experimental science, it is allowable for us 

 to consider what satisfaction steam, electricity, and such accumu- 

 lators of energy as India rubber, steel, compressed air, gas motors, 

 and explosives may give. We are able now, with special pre- 

 cautions, to construct steam motors of extreme levity, and giving 

 one horse-power for a weight very near that of 3'5 kilogrammes ; 

 but if we add to them the indispensable generator and the inevi- 

 table propeller, the weight increases in formidable proportions, 

 and the system becomes inapplicable to any mode of support in 

 the air. 



Electricity, although it is better in many respects, is likewise 

 liable to criticism. Yet we had the honor of performing some 

 satisfactory experiments with it in 1887 at the Scientific Congress 

 in Toulouse, and in 1888 at the Easter session of the /Socie/e de Phy- 

 sique. We had taken all possible care in the construction of a 

 motor ; it was all of aluminum, with the exception of the poles, 

 which were of soft iron. Its weight was ninety grammes, and its 

 ppwer, measured with our dynamometer, was maintained at two 

 kilogrammetres, corresponding exactly with one horse-power per 

 3"375 kilogrammes. This motor, armed with a light and geomet- 

 rically perfect helix, made accord- 

 ing to a new method which we 

 had explained to the Academy of 

 Sciences on the 12th of July, 1886, 

 was placed in one of the plates of 

 a balance, and put in connection, 

 with a constant electrical source 

 of forty watts, when it raised its 

 whole weight. In order to render 

 more visible the extent of the re- 

 sult, and obtain a more exact idea 

 of it, I arranged a light balance 

 with long arms, to one of which 

 I attached the motor experiment- 

 ed on, as in Fig. 2. The electric ^'''- 2--Electbic Helicopter and Aero- 



communications, carried through 



the foot, knife-edges, and arms of the balance, can not obstruct 

 the freedom of its motion. Being movable in the vertical and 

 horizontal directions, the balance changes immediately from the 

 position A B to that of A' B'. The power developed by the 

 motor is found, by the most careful measurement, equivalent 

 to two kilogrammes— a power so related to the weight of the 

 motor as to be capable of raising it vertically twenty -two 



