h only the
title, "That the earth moves and the heaven is still," has survived.
Some years later Copernicus wrote a short summary of his book, for
private circulation only, entitled "A Short commentary on his
hypotheses concerning the celestial movements." A fuller account of
them was given by his friend and disciple, [Sidenote: _Narratio prima_,
1540] George Joachim, called Rheticus, who left Wittenberg, where he
was teaching, to sit at the master's feet, and who published what was
called _The First Account_.

Finally, Copernicus was persuaded to give his own work to the public.
Foreseeing the opposition it was likely to call forth, he tried to
forestall criticism by a dedication to the Pope Paul III. Friends at
Nuremberg undertook to find a printer, and one of them, the Lutheran
pastor Andrew Osiander, with the best intentions, did the great wrong
of inserting an anonymous preface stating that the author did not
advance his hypotheses as necessarily true, but merely as a means of
facilitating astronomical calculations. At last the greatest work of
the century, _On the Revolutions of the Heavenly Spheres_, [Sidenote:
De revolutionibus orbium caelestium, 1543] came from the press; a copy
was brought to the author on his death bed.

The first of the six books examines the previous authorities, the
second proposes the new theory, the third discusses the precession of
the equinoxes, the fourth proves that the moon circles the earth, the
fifth and most important proves that the planets, including the earth,
move around the sun, and gives correctly the time of the orbits of all
the planets then known, from Mercury with eighty-eight days to Saturn
with thirty {621} years. The sixth book is on the determination of
latitude and longitude from the fixed stars. Copernicus's proofs and
reasons are absolutely convincing and valid as far as they go. It
remained for Galileo and Newton to give further explanations and some
modifications in detail of the new theory.

[Sidenote: Reception of the Copernican theory]

When one remembers the enormous hubbub raised by Darwin's _Origin of
Species_, the reception of Copernicus's no less revolutionary work
seems singularly mild. The idea was too far in advance of the age, too
great, too paradoxical, to be appreciated at once. Save for a few
astronomers like Rheticus and Reinhold, hardly anyone accepted it at
first. It would have been miraculous had they done so.

Among the first