outermost planet and the fixed stars.

We are bound to admit that in the circumstances of the case, so long
as there was no question of dynamical forces connecting the members of
the solar system, his reasoning, as we should expect from such a man,
is practical and sound. It is not surprising, then, that astronomers
generally did not readily accept the views of Copernicus, that Luther
(Luther's _Tischreden_, pp. 22, 60) derided him in his usual pithy
manner, that Melancthon (_Initia doctrinae physicae_) said that
Scripture, and also science, are against the earth's motion; and that
the men of science whose opinion was asked for by the cardinals (who
wished to know whether Galileo was right or wrong) looked upon
Copernicus as a weaver of fanciful theories.

Johann Kepler is the name of the man whose place, as is generally
agreed, would have been the most difficult to fill among all those who
have contributed to the advance of astronomical knowledge. He was born
at Wiel, in the Duchy of Wurtemberg, in 1571. He held an appointment
at Gratz, in Styria, and went to join Tycho Brahe in Prague, and to
assist in reducing his observations. These came into his possession
when Tycho Brahe died, the Emperor Rudolph entrusting to him the
preparation of new tables (called the Rudolphine tables) founded on
the new and accurate observations. He had the most profound respect
for the knowledge, skill, determination, and perseverance of the man
who had reaped such a harvest of most accurate data; and though Tycho
hardly recognised the transcendent genius of the man who was working
as his assistant, and although there were disagreements between them,
Kepler held to his post, sustained by the conviction that, with these
observations to test any theory, he would be in a position to settle
for ever the problem of the solar system.