gs is apparently
ten thousand times greater than the resistance of their weight,' is
erroneous, of course, but study of the translation from which the
foregoing excerpt is taken will show that the error detracts very little
from the value of the work itself. Borelli sets out very definitely
the mechanism of flight, in such fashion that he who runs may read. His
reference to 'the use of a large vessel,' etc., concerns the suggestion
made by Francesco Lana, who antedated Borelli's publication of De Motu
Animalium by some ten years with his suggestion for an 'aerial ship,' as
he called it. Lana's mind shows, as regards flight, a more imaginative
twist; Borelli dived down into first causes, and reached mathematical
conclusions; Lana conceived a theory and upheld it--theoretically, since
the manner of his life precluded experiment.

Francesco Lana, son of a noble family, was born in 1631; in 1647 he was
received as a novice into the Society of Jesus at Rome, and remained
a pious member of the Jesuit society until the end of his life. He was
greatly handicapped in his scientific investigations by the vows
of poverty which the rules of the Order imposed on him. He was more
scientist than priest all his life; for two years he held the post of
Professor of Mathematics at Ferrara, and up to the time of his death,
in 1687, he spent by far the greater part of his time in scientific
research, He had the dubious advantage of living in an age when one man
could cover the whole range of science, and this he seems to have
done very thoroughly. There survives an immense work of his entitled,
Magisterium Naturae et Artis, which embraces the whole field of
scientific knowledge as that was developed in the period in which Lana
lived. In an earlier work of his, published in Brescia in 1670, appears
his famous treatise on the aerial ship, a problem which Lana worked out
with thoroughness. He was unable to make practical experiments, and thus
failed to perceive the one insuperable drawback to his project--of which
more anon.

Only extracts from the translation of Lana's work can be given here, but
sufficient can be given to show fully the means by which he designed to
achieve the conquest of the air. He begins by mention of the celebrated
pigeon of Archytas the Philosopher, and advances one or two theories
with regard to the way in which this mechanical bird was constructed,
and then he recites, apparently with full belief in it, the fable of