Francesco Lana, with his 'aerial ship,' stands as one of the
first great exponents of aerostatics; up to the time of the
Montgolfier and Charles balloon experiments, aerostatic and
aerodynamic research are so inextricably intermingled that it
has been thought well to treat of them as one, and thus the work
of Lana, Veranzio and his parachute, Guzman's frauds, and the
like, have already been sketched. In connection with Guzman,
Hildebrandt states in his Airships Past and Present, a fairly
exhaustive treatise on the subject up to 1906, the year of its
publication, that there were two inventors--or
charlatans--Lorenzo de Guzman and a monk Bartolemeo Laurenzo,
the former of whom constructed an unsuccessful airship out of a
wooden basket covered with paper, while the latter made certain
experiments with a machine of which no description remains. A
third de Guzman, some twenty-five years later, announced that he
had constructed a flying machine, with which he proposed to fly
from a tower to prove his success to the public. The lack of
record of any fatal accident overtaking him about that time
seems to show that the experiment was not carried out.

Galien, a French monk, published a book L'art de naviguer dans
l'air in 1757, in which it was conjectured that the air at high
levels was lighter than that immediately over the surface of
the earth. Galien proposed to bring down the upper layers of
air and with them fill a vessel, which by Archimidean principle
would rise through the heavier atmosphere. If one went high
enough, said Galien, the air would be two thousand times as
light as water, and it would be possible to construct an
airship, with this light air as lifting factor, which should be