RESULTS IN AERIAL NAVIGATION. 559 



" Aluminum bronze, ten parts aluminum and ninety parts copper, has a spe- 

 cific gravity of only 7.69. It is three times more rigid than gun metal, and forty- 

 four times more so than brass; and, in consequence of its transverse, tensile and 

 elastic strength, exceedingly strong tubing and rods could be made of it, at a vast 

 economy of structural weight." 



Professor Newberry now tells you that "aluminum, (it is time that metal- 

 lurgists should make a final choice between the terminations in inum and inium,) 

 has not been largely used yet, because of the cost that has attended its produc- 

 tion, but for a long time everybody has been looking for a cheaper method. The 

 price of it when I first saw it was $8 an ounce, a year ago it was $1 an ounce, and 

 now there is a Philadelphia firm that offers to supply it in large quantities at 40 

 cents an ounce, while a Connecticut manufacturing company say they that can 

 produce it for less." He continues : " Think how valuable it would be in bridges 

 and all structures in which lightness combined with strength and durability is de- 

 sired. 7/ we ever have, machines to navigate the air it will be an extremely important 

 element, for it can be easily wrought into tubes that will be strong and light. " 



It is not within my province to enlage upon the thousand departments in 

 which this light, strong and non-corrosive metal will take the place of iron. And 

 we have yet to learn how cheap is the new method of its production, but if your 

 London telegram is well-founded, and if the cost of aluminum can be reduced to 

 any sum approximating the cost of steel, making allowance for the difference in 

 specific gravity of the two substances, we can safely assert that the year 1882 has 

 provided two of the three factors required for the solution of the problem of aerial 

 navigation. 



The public may remember that an imperfect machine, in some features re- 

 sembling my design, has lately achieved a measure of success in France. M. Tis 

 sandier is now constructing a spindle-shaped acrobat to be driven by electricity. 

 Owing partly to its disadvantageous separation of the car and aerostat, its speed 

 will not exceed fifteen miles an hour in calm weather. 



In Mr. Chanute's " Annual Address," 1880, before the convention of the 

 American Society of Civil Engineers, he spoke as follows : 



"There are signs that a new motive power will be invented, which shall be 

 safer, of greater energy, and less wasteful than steam. You know that chemists 

 tell us that the theoretical energy of a pound of coal varies between eight and 

 eleven millions of feet pounds, while we utilize with our best steam engines but 

 from three to eleven per cent of the theoretical value of the fuel. I think it not 

 impossible that we shall perfect methods of employing directly the gases produced 

 from our fuels (instead of using them to generate another gas out of water), and 

 thus obtain better economical results than with steam. I know of several prom- 

 ising attempts in this direction. 



" And, with a new motive power, perhaps will come the solution of the last 

 transportation problem which remains to be solved. I suppose yoa will smile 

 when I say that the atmosphere still remains to be conquered ; but wildly improb- 



