enough, there would be the opposite effect to that expected by the opponents of Copernicus. The
top of the tower, being further from the centre of the earth than the bottom, is moving faster, and
therefore the stone should fall slightly to the east of the foot of the tower. This effect, however,
would be too slight to be measurable.
Galileo ardently adopted the heliocentric system; he corresponded with Kepler, and accepted his
discoveries. Having heard that a Dutchman had lately invented a telescope, Galileo made one
himself, and very quickly discovered a number of important things. He found that the Milky Way
consists of a multitude of separate stars. He observed the phases of Venus, which Copernicus
knew to be implied by his theory, but which the naked eye was unable to perceive. He discovered
the satellites of Jupiter, which, in honour of his employer, he called "sidera medicea." It was found
that these satellites obey Kepler's laws. There was, however, a difficulty. There had always been
seven heavenly bodies, the five planets and the sun and moon; now seven is a sacred number. Is
not the Sabbath the seventh day? Were there not the seven-branched candlesticks and the seven
churches of Asia? What, then, could be more appropriate than that there should be seven heavenly
bodies? But if we have to add Jupiter's four moons, that makes eleven--a number which has no
mystic properties. On this ground the traditionalists denounced the telescope, refused to look
through it, and maintained that it revealed only delusions. Galileo wrote to Kepler wishing they
could have a good laugh together at the stupidity of "the mob"; the rest of his letter makes it plain
that "the mob" consisted of the professors of philosophy, who tried to conjure away Jupiter's
moons, using "logic-chopping arguments as though they were magical incantations."
Galileo, as every one knows, was condemned by the Inquisition, first privately in 1616, and then
publicly in 1633, on which latter occasion he recanted, and promised never again to maintain that
the earth rotates or revolves. The Inquisition was successful in putting an end to science in Italy,
which did not revive there for centuries. But it failed to prevent men of science from adopting the
heliocentric theory, and did considerable damage to the Church by its stupidity. Fortunately there
were Protestant countries, where the clergy, however anxious to do harm to science, were unable
to gain control of the State.