that Mr. Gower
was subsequently blown out to sea with his balloon, leaving no trace
behind.

At this stage it will be well to glance at some of the more important
theories which were being mooted as to the possibility of aerial
locomotion properly so called. Broadly, there were two rival schools
at this time. We will call them the "lighter-than-air-ites" and the
"heavier-than-air-ites," respectively. The former were the advocates
of the air vessel of which the balloon is a type. The latter school
maintained that, as birds are heavier than air, so the air locomotive
of the future would be a machine itself heavier than air, but capable
of being navigated by a motor yet to be discovered, which would develop
proportionate power. Sir H. Maxim's words may be aptly quoted here. "In
all Nature," he says, "we do not find a single balloon. All Nature's
flying machines are heavier than the air, and depend altogether upon the
development of dynamic energy."

The faculty of soaring, possessed by many birds, of which the albatross
may be considered a type, led to numerous speculations as to what would
constitute the ideal principle of the air motor. Sir G. Cayley, as
far back as 1809, wrote a classical article on this subject, without,
however, adding much to its elucidation. Others after his time conceived
that the bird, by sheer habit and practice, could perform, as it were,
a trick in balancing by making use of the complex air streams varying in
speed and direction that were supposed to intermingle above.

Mr. R. A. Proctor discusses the matter with his usual clear-sightedness.
He premises that the bird may, in actual fact, only poise itself
for some ten minutes--an interval which many will consider far too
small--without flap of the wings, and, while contending that the problem
must be simply a mechanical one, is ready to admit that "the sustaining
power of the air on bodies of a particular form travelling swiftly
through it may be much greater or very different in character from what
is supposed." In his opinion, it is a fact that a flat body travelling
swiftly and horizontally will sink towards the ground much more slowly
than a similar body moving similarly but with less speed. In proof of
this he gives the homely illustration of a flat stone caused to make
"ducks and drakes." Thus he contends that the bird accomplishes its
floating feat simply by occasional powerful propulsive efforts, combined
with perfect balance. From