attempts were made to deflect or guide its
course by the use of oars. Those who made these attempts were almost
unanimous in declaring that the use of oars enabled them to alter the
course of a balloon by several points of the compass. Another method of
steering employed sails, held up to the wind by the drag of a guide-rope
on the ground. The control to be obtained by means like these was
pathetically small, and the real problem was soon seen to be the problem
of a motor. The spherical balloon is obviously unsuited for
power-navigation; in 1784, only a year after the invention of the
balloon, General Meusnier, of the French army, made designs for an
egg-shaped power-balloon to be driven by three airscrews, supported on
the rigging between the car and the balloon. To keep the balloon fully
inflated and stiff, in order to drive it against the wind, he planned a
double envelope, the inner space to contain hydrogen, the outer space to
be pumped full of air. He may thus be said to have invented the
ballonet, or air-chamber of the balloon, and to be the father of later
successful airships. His designs were mere descriptions; they could not
be carried out; there was at that time no light engine in existence, and
his own suggestion that the airscrews should be worked by manual labour
may be called a design for an engine that weighs something over half a
ton for every horse-power of energy exerted. In 1798 the French author
Beaumarchais recommended the construction of airships in the long shape
of a fish. As the years passed, models were made on this plan. In 1834
Mr. Monck Mason exhibited at the Lowther Arcade in London a model
airship, thirteen and a half feet long, and six and a half feet in
diameter; its airscrew was operated by a spring; it was fitted with
horizontal planes for setting its course; and in its very short flights
it attained a speed of something over five miles an hour. A larger
model, with two airscrews driven by clockwork, was exhibited in 1850 by
M. Jullien, a clockmaker of Paris, and flew successfully against a
slight breeze. The first successful man-carrying airship was built in
1852 by Henry Giffard, the French engineer, and was flown at Paris on
the 24th of September in that year. It was spindle-shaped, with a
capacity of 87,000 cubic feet, and a length of 144 feet. The airscrew,
ten feet in diameter, was driven by a steam-engine of three horse-power,
and the speed attained was about six miles an hour. I