FLIGHT AND ITS IMITATION. 
401 
It is evident that if the wing surface could be extended longi- 
tudinally and there attached, something like the small end of a 
kite, to the extremity of its backbone, thirty feet behind, the 
surface thus exposed might be made ample enough to sustain 
man and motive power. In fact, it would be easy so to extend 
300 or 400 feet of canvas by wing arms, twenty feet long 
from tip to tip ; but the surface would not be in tension . 
It may have been observed that the best flying kites are 
those which 44 belly ” with the wind, or in other words, form a 
concave towards the wind. Would such an arrangement prove 
effective ? If so, then I can see safety under such an extent of 
surface. I can also see that this surface would take a concave 
form in its descent, and so prove to be a longitudinal parachute 
which would bring a weight down in perfect safety. 
Is there any example in Nature which would warrant the sup- 
position that such an arrangement would be effective ? Well, 
if we go to an aquarium, and watch the mode of progression of 
some fishes, we shall find that some of the flat-fish — notably 
the skate — progress by a wave-like action of the whole of their 
bodies. We cannot, of course, impart a wave action to the 
framework which shall extend our canvas, but we can do so to 
the canvas, and the question arises, Will a surface so vibrated 
support as well as propel ? I can aver that a model made upon 
this principle, which I discovered for myself, behaved in a per- 
fectly satisfactory manner. The wave action is imparted to it 
by the vibration of two wing arms, winch cause a succession of 
waves to flow from the front to the extreme end ; and I find that 
it will not be difficult to manufacture those arms twenty-four 
feet from tip to tip, light, elastic, and incapable of fracture, 
consisting, as they will, of bundles of canes wrapped together 
firmly, from base to tip, with whipcord, and tapering the whole 
by cutting off a cane every foot or so. My idea is, that if the 
whole were placed upon wheels, and a wave action imparted to 
the fabric by steam or compressed air, it would perform much the 
same feat as Mr. Wenham’s eagle. The parachute action upon 
cessation of motion leaves nothing to be desired, amenable as 
it is to proper management in the disposal of the ballast. 
The sustentation of a weight in flight by wing action de- 
pends entirely upon power, strength of material, and surface. 
As power and strength are increased, the surface may be cur- 
tailed. I scarcely, however, dare to hope for any such result as 
spoken of by Sir George Cayley, for in that case I might expect 
that 400 square feet of canvas would support more than 800 
pounds. 
The surface, however, being its own propeller, satisfactory 
results may be expected. I have a model, for instance, of the 
dimensions of an albatross. Now if it is supposed that a fabric 
NEW SERIES, VOL. III. — NO. XII. D D 
