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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
chimerical in its form, looked at in view of the conditions of
aerial navigation, but much more singular. Galien describes his
air-boat, in 1755, in his little work entitled, "The Art of
Sailing in the Air." His project was a most extraordinary one,
and its boldness is only equalled by the seriousness of the
narrative. According to him, the atmosphere is divided into two
horizontal layers, the upper of which is much lighter than the
lower. "But," says Galien, "a ship keeps its place in the water
because it is full of air, and air is much lighter than water.
Suppose, then, that there was the same difference of weight
between the upper and the lower layer of air as there is between
the lower stratum and water; and suppose, also, a boat which
rested upon the lower layer of air, with its bulk in the lighter
upper layer--like a ship which has its keel in the water but its
bulk in the air--the same thing would happen with the air-ship as
with the water-ship--it would float in the denser layer of air."
Galien adds that in the region of hail there was in the air a
separation into two layers, the weights of which respectively are
as 1 to 2. "Then," says he, "in placing an air-boat in the region
of hail, with its sides rising eighty-three fathoms into the
upper region, which is much more light, one could sail
perfectly."
But how to get this enormous air-boat up to the region of hail?
This is a minor detail, respecting which Galien is not clear.
From the labours of Lana and Galien, with their impossible flying
machines, the inventor of the balloon could derive no benefit
whatever; nor is his fame to be in the least diminished because
many had laboured in the same field before him. Nor can the story
of the ovoador, or flying man, a legend very confused, and of
which there are many versions, have given to Montgolfier any
valuable hints. It appears that a certain Laurent de Guzman, a
monk of Rio Janeiro, performed at Lisbon before the king, John
V., raising himself in a balloon to a considerable height. Other
versions of the story give a different date, and assign the
pretended ascent to 1709. The above engraving, extracted from
the "Bibliotheque de la Rue de Richelieu," is an exact copy of
Guzman's supposed balloon.
In 1678 a mechanician of Salle, in Maine, named Besnier invented
a flying-machine. The machine consisted of four great wings, or
paddles, mounted at the extremities of levers, which rested on
the shoulders of the man who guided it, and who could move them
alternately by means of his hands and feet. The following
description of the machine is given in the Journal de Paris by an
eye-witness:
"The 'wings' are oblong frames, covered with taffeta, and
attached to the ends of two rods, adjusted on the shoulders The
wings work up and down. Those in front are worked by the hands;
those behind by the feet, which are connected with the ends of
the rods by strings. The movements were such that when the right
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