in his body than that reflected rays are the sole cause of
Galileo's erroneous observations. In regard to the third question, he
says that these planets are like the smallest fly compared to an
elephant; and, finally, concludes on the fourth, that the only use of
them is to gratify Galileo's "thirst of gold," and to afford himself a
subject of discussion.'[7] Galileo did not condescend to take any notice
of this scurrilous production; but Horky, who imagined that he had done
something clever, sent a copy of his pamphlet to Kepler. In a few days
after he called to see him, and was received with such a storm of
indignation that he begged for mercy and implored his forgiveness.
Kepler forgave him, but insisted on his making amends. He writes: 'I
have taken him again into favour upon this preliminary condition, to
which he has agreed--that I am to show him Jupiter's satellites, _and he
is to see them_, and own that they are there.'

The evidence in support of the existence of Jupiter's satellites became
so conclusive that the opponents of Galileo were compelled to renounce
their disbelief in those bodies, whether real or pretended. The Grand
Duke, preferring to trust to his eyes rather than believe in the
arguments of the professor at Padua, observed the satellites on several
occasions, along with Galileo, at Pisa, and on his departure bestowed
upon him a gift of one thousand florins. Several of Galileo's enemies,
as a result of their observations, now arrived at the conclusion that
his discovery was incomplete, and that Jupiter had more than four
satellites in attendance upon him. Scheiner counted five, Rheita nine,
and other observers increased the number to twelve. But it was found to
be quite as hazardous to exceed the number stated by Galileo as it was
to deny the existence of any; for, when Jupiter had traversed a short
distance of his path among the fixed stars, the only bodies that
accompanied him were his four original attendants, which continued to
revolve round him with unerring regularity in every part of his orbit.

Galileo did not afford his opponents much time to oppose or controvert
with argument the discoveries made by him with the telescope before his
announcement of a new one attracted public attention from those already
known. He, however, exercised greater caution in disclosing the results
of his observations, as other persons laid claim to having made similar
discoveries prior to the time at which his