e same extent has existed in
no other science, viz.: that all the leading phenomena are in their
appearance delusive. It is indeed true that in all sciences superficial
observation can only lead, except by chance, to superficial knowledge;
but I know of no branch in which, to the same degree as in astronomy,
the great leading phenomena are the reverse of true; while they yet
appeal so strongly to the senses, that men who could foretell eclipses,
and who discovered the precession of the equinoxes, still believed that
the earth was at rest in the center of the universe, and that all the
host of heaven performed a daily revolution about it as a center.

It usually happens in scientific progress, that when a great fact is at
length discovered, it approves itself at once to all competent judges.
It furnishes a solution to so many problems, and harmonizes with so many
other facts,--that all the other _data_ as it were crystallize at once
about it. In modern times, we have often witnessed such an impatience,
so to say, of great truths, to be discovered, that it has frequently
happened that they have been found out simultaneously by more than one
individual; and a disputed question of priority is an event of very
common occurrence. Not so with the true theory of the heavens. So
complete is the deception practiced on the senses, that it failed more
than once to yield to the suggestion of the truth; and it was only when
the visual organs were armed with an almost preternatural instrumental
power, that the great fact found admission to the human mind.

THE COPERNICAN SYSTEM.

It is supposed that in the very dawn of science, Pythagoras or his
disciples explained the apparent motion of the heavenly bodies about the
earth by the diurnal revolution of the earth on its axis. But this
theory, though bearing so deeply impressed upon it the great seal of
truth, _simplicity_, was in such glaring contrast with the evidence of
the senses, that it failed of acceptance in antiquity or the middle
ages. It found no favor with minds like those of Aristotle, Archimedes,
Hipparchus, Ptolemy, or any of the acute and learned Arabian or mediaeval
astronomers. All their ingenuity and all their mathematical skill were
exhausted in the development of a wonderfully complicated and ingenious,
but erroneous history. The great master truth, rejected for its
simplicity, lay disregarded at their feet.

At the second dawn of scienc