at suspended from the machine a man was to sit and direct
the whole by the opening and shutting of valves.

Another scheme, more ingenious but not less fallacious, was propounded
in 1670 by Francis Lana, a Jesuit, for navigating the air. This plan
was to make four copper balls of very large dimensions, yet so extremely
thin that, after the air had been extracted, they should become, in a
considerable degree, specifically lighter than the surrounding medium.
Each of his copper balls was to be about 25 feet in diameter, with the
thickness of only the 225th part of an inch, the metal weighing 365
pounds avoirdupois, while the weight of the air which it should contain
would be about 670 pounds, leaving, after a vacuum had been formed, an
excess of 305 pounds for the power of ascension. The four balls would
therefore, it was thought, rise into the air with a combined force of
1220 pounds, which was deemed by Lana to be sufficient to transport a
boat completely furnished with masts, sails, oars, and rudders, and
carrying several passengers. The method by which the vacuum was to be
obtained was by connecting each globe, fitted with a stop-cock, to a
tube of at least thirty-five feet long; the whole being filled with
water; when raised to the vertical position the water would run out, the
stop-cocks would be closed at the proper time, and the vacuum secured.
It does not seem to have entered the head of this philosopher that the
weight of the surrounding atmosphere would crush and destroy his thin
exhausted receivers, but he seems to have been alarmed at the idea of
his supposed discovery being applied to improper uses, such as the
passing of desperadoes over fortified cities, on which they might rain
down fire and destruction from the clouds!

Perhaps the grandest of all the fanciful ideas that have been
promulgated on this subject was that of Galien, a Dominican friar, who
proposed to collect the fine diffused air of the higher regions, where
hail is formed, above the summit of the loftiest mountains, and to
enclose it in a cubical bag of enormous dimensions--extending more than
a mile every way! This vast machine was to be composed of the thickest
and strongest sail-cloth, and was expected to be capable of transporting
through the air a whole army with all their munitions of war!

There were many other devices which men hit upon, some of which embraced
a certain modicum of truth mixed with a large proportion of fallacy.