great merit of Bacon's work, however, depends on the principles
taught as regards experiment and the observation of nature, rather than
on any single invention. He had the all-important idea of breaking with
tradition. He championed unfettered inquiry in every field of thought.
He had the instinct of a scientific worker--a rare instinct indeed in
that age. Nor need we doubt that to the best of his opportunities he was
himself an original investigator.

LEONARDO DA VINCI

The relative infertility of Bacon's thought is shown by the fact that he
founded no school and left no trace of discipleship. The entire century
after his death shows no single European name that need claim the
attention of the historian of science. In the latter part of the
fifteenth century, however, there is evidence of a renaissance of
science no less than of art. The German Muller became famous under
the latinized named of Regio Montanus (1437-1472), although his actual
scientific attainments would appear to have been important only in
comparison with the utter ignorance of his contemporaries. The most
distinguished worker of the new era was the famous Italian Leonardo da
Vinci--a man who has been called by Hamerton the most universal genius
that ever lived. Leonardo's position in the history of art is known to
every one. With that, of course, we have no present concern; but it is
worth our while to inquire at some length as to the famous painter's
accomplishments as a scientist.

From a passage in the works of Leonardo, first brought to light by
Venturi,(1) it would seem that the great painter anticipated Copernicus
in determining the movement of the earth. He made mathematical
calculations to prove this, and appears to have reached the definite
conclusion that the earth does move--or what amounts to the same thing,
that the sun does not move. Muntz is authority for the statement that
in one of his writings he declares, "Il sole non si mouve"--the sun does
not move.(2)

Among his inventions is a dynamometer for determining the traction power
of machines and animals, and his experiments with steam have led some
of his enthusiastic partisans to claim for him priority to Watt in the
invention of the steam-engine. In these experiments, however, Leonardo
seems to have advanced little beyond Hero of Alexandria and his steam
toy. Hero's steam-engine did nothing but rotate itself by virtue of
escaping jets of steam forced from the bent tubes, while