up in the air, and which would attract and draw up the balloon.
The wiseacre who invented these modes of flying in the air seems,
some would say, to have been more in want of very strict
confinement on the earth than of the freedom of the skies.

In 1670 Francis Lana constructed the flying-machine shown on the
next page. The specific lightness of heated air and of hydrogen
gas not having yet been discovered, his only idea for making his
globes rise was to take all the air out of them. But even
supposing that the globes were thus rendered light enough to
rise, they must inevitably have collapsed under the atmospheric
pressure.

As for the idea of making use of a sail to direct the balloon, as
one directs a vessel, that also was a delusion; for the whole
machine, globes and sails, being freely thrown into the air,
would infallibly follow the direction of the wind, whatever that
might be. When a ship lies in the sea, and its sails are
inflated with the wind, we must remember that there are two
forces in operation--the active force of the wind and the passive
force of the resistance of the water; and in working these forces
the one against the other, the sailor can turn within a point of
any direction he pleases. But when we are subjected wholly to a
single force, and have no point of support by the use of which to
turn that force to our own purposes, as is the case with the
aeronaut, we are entirely at the mercy of that force, and must
obey it.

After the flying-machine of Lana there was constructed by Galien
(who, like the former, was an ecclesiastic) an air-boat, less