wing span of about 50 ft.; the motive power for this was
supplied by steam from a boiler which, being stationary on the
ground, was connected by a length of hose to the machine. De
Villeneuve, turning on steam for his first trial, obtained
sufficient power to make the wings beat very forcibly; with the
inventor on the machine the latter rose several feet into the
air, whereupon de Villeneuve grew nervous and turned off the
steam supply. The machine fell to the earth, breaking one of
its wings, and it does not appear that de Villeneuve troubled to
reconstruct it. This experiment remains as the greatest success
yet achieved by any machine constructed on the ornithopter
principle.

It may be that, as forecasted by the prophet Wells, the
flapping-wing machine will yet come to its own and compete with
the aeroplane in efficiency. Against this, however, are the
practical advantages of the rotary mechanism of the aeroplane
propeller as compared with the movement of a bird's wing, which,
according to Marey, moves in a figure of eight. The force
derived from a propeller is of necessity continual, while it is
equally obvious that that derived from a flapping movement is
intermittent, and, in the recovery of a wing after completion of
one stroke for the next, there is necessarily a certain
cessation, if not loss, of power.

The matter of experiment along any lines in connection with
aviation is primarily one of hard cash. Throughout the whole
history of flight up to the outbreak of the European war
development has been handicapped on the score of finance, and,
since the arrival of the aeroplane, both ornithopter and