1893.] NEW YORK ACADEMY OF SCIENCES. 87 



Here, then, is a theoretical boomerang. "Will it go? Permit 

 me to add here what may strike you as a curious oversight. 

 Up to this time T had never seen a boomerang to notice it. In 

 the light of all I had read about the extreme difficulty of making 

 a good one, I took good care that no one was around to observe 

 my first attempt at hand throAving. The narrative may interest 

 joa. I found an open space behind a pile of lumber. I looked 

 all about. I was alone. I determined to make a light throw 

 at first, and the first thing that astonished me was the comj^ara- 

 tively enormous distance that it travelled upon a slight impulse. 

 Its weight was less than two ounces, and yet it went over 200 

 feet away. It rose swiftly in the air, whirling and flashing in 

 the sunlight, and, as I thought, extremel}' beautiful in the 

 graceful ease of its motions. And could I believe my eyes! 

 Yes ! it was coming back. It fell within a yard or two of my 

 feet. I picked it up, fully as delighted as ever that black 

 savage could have been who stumbled upon its first discovery, 

 and became a blessing to his race. 



I have so far carefully noted inaccuracies in defining the 

 characteristic motions of the boomerang. Permit me to add 

 still further of the distinct peculiarity of the boomerang : 



That in its motion of translation, its axis of figure turns 

 longitudinally with it — a requii-ement as incompatible with the 

 proper action of a wind-mill or a screw propeller as tipping a 

 wheelbarrow bodily, end over end, would be difficult comj^ared 

 with its proper use. 



Its real motions, then, correctly apprehended, practically 

 ■constitute the instrument an aeroplane, pure and simple, in 

 which no screw-shape warp or convex surface is required. 



It is a projectile with an excessive sensitiveness to atmos- 

 pheric influences, to be controlled in flight by the qualitative 

 and quantitative character of the mechanical projection to be 

 imparted to it. What shall be the ratio of the speed of gyra- 

 tion to that of transition? Is there a limit to attain? For I am 

 seeking to obtain an ideal flight by mechanical means. That 

 is to say, one which shall be straight away, shall rise and soar 

 and return, without veering far from a vertical plane. 



It is well known that the flight of the Australian boomerang 

 is invariably in a more or less circular orbit. Its motions when 

 thrown by the hand are comparatively slow. I therefore 

 furnished my machine with the means of increasing the speed 

 at will, and of adjusting the relative speed of one motion to the 

 other. 



In this connection it may be interesting to note the remark- 

 able discovery of Scott Eussell, viz : 



