THE TRIUMPH OF THE AEROPLANE 



one second. It is evident that he would thus distribute 

 his weight over the same amount of ice as if the cakes 

 were fastened together in a solid piece. 



"So it is with the air," says Professor Langley. 

 "Even the viewless air possesses inertia; it cannot be 

 pushed aside without some effort; and while the por- 

 tion which is directly under the air-ship would not keep 

 it from falling several yards in the first second, if the 

 ship goes forward so that it runs or treads on thousands 

 of such portions in that time, it will sink in proportion- 

 ately less degree; sink, perhaps only through a frac- 

 tion of an inch." 



It is evident, therefore, that if, at a given speed, the 

 horizontal wings of an air-ship would keep it from fall- 

 ing more than a fraction of an inch in a second, by 

 increasing the speed sufficiently and giving the wings 

 an upward inclination, the air-ship instead of falling 

 might actually rise. And this, as we shall see presently, 

 is just what the flying-machines of Sir Hiram Maxim 

 and Professor Langley and of the Wright brothers 

 and their imitators did do. 



langley's early experiments and discoveries 



It was while making an important series of experi- 

 ments with aeroplanes that Professor Langley made 

 the discovery which has since been known as "Langley*s 

 Law.'* In effect this law is that while it takes a certain 

 strain to sustain a properly disposed weight while 

 stationary in the air, to advance the weight rapidly 

 takes even less strain than when the weight is station- 



[275] 



