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 I 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 throwing. The narrative may interest 
you. 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 compara- 
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, extremely 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 requirement 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 compared 
with its proper use. 
Its real motions, then, correctly apprehended, practically 
constitute the instrument an eroplane, 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 Russell, viz : 
