did not succeed in flying, if he had most of the component parts
of an aeroplane as we know it to-day?

The answer to the second question is that Sir George did not fly,
simply because there was no light petrol motor in existence; the
crude motors in use were far too heavy, in proportion to the
power developed, for service in a flying machine. It was
recognized, not only by Sir George, but by many other English
engineers in the first half of the nineteenth century, that as
soon as a sufficiently powerful and light engine did appear, then
half the battle of the conquest of the air would be won.

But his prophetic voice was of the utmost assistance to such
inventors as Santos Dumont, the Wright brothers, M. Bleriot, and
others now world-famed. It is quite safe to assume that they
gave serious attention to the views held by Sir George, which
were given to the world at large in a number of highly-interest-
ing lectures and magazine articles. "Ideas" are the very
foundation-stones of invention--if we may be allowed the figure
of speech--and Englishmen are proud, and rightly proud, to number
within their ranks the original inventor of the heavier-than-air
machine.



CHAPTER XVI
The "Human Birds"

For many years after the publication of Sir George Cayley's
articles and lectures on aviation very little was done in the way