to the class of small farmers, on the 28th of March, 1749; he died on
the 5th of March, 1827.

The first and second volumes of the _Mecanique Celeste_ were published
in 1799; the third volume appeared in 1802, the fourth volume in 1805;
as regards the fifth volume, Books XI. and XII. were published in 1823,
Books XIII. XIV. and XV. in 1824, and Book XVI. in 1825. The _Theorie
des Probabilites_ was published in 1812. We shall now present the reader
with the history of the principal astronomical discoveries contained hi
these immortal works.

Astronomy is the science of which the human mind may most justly boast.
It owes this indisputable preeminence to the elevated nature of its
object, to the grandeur of its means of investigation, to the certainty,
the utility, and the unparalleled magnificence of its results.

From the earliest period of the social existence of mankind, the study
of the movements of the heavenly bodies has attracted the attention of
governments and peoples. To several great captains, illustrious
statesmen, philosophers, and eminent orators of Greece and Rome it
formed a subject of delight. Yet, let us be permitted to state,
astronomy truly worthy of the name is quite a modern science. It dates
only from the sixteenth century.

Three great, three brilliant phases, have marked its progress.

In 1543 Copernicus overthrew with a firm and bold hand, the greater part
of the antique and venerable scaffolding with which the illusions of the
senses and the pride of successive generations had filled the universe.
The earth ceased to be the centre, the pivot of the celestial movements;
it henceforward modestly ranged itself among the planets; its material
importance, amid the totality of the bodies of which our solar system is
composed, found itself reduced almost to that of a grain of sand.

Twenty-eight years had elapsed from the day when the Canon of Thorn
expired while holding in his faltering hands the first copy of the work
which was to diffuse so bright and pure a flood of glory upon Poland,
when Wuertemberg witnessed the birth of a man who was destined to achieve
a revolution in science not less fertile in consequences, and still more
difficult of execution. This man was Kepler. Endowed with two qualities
which seemed incompatible with each other, a volcanic imagination, and a
pertinacity of intellect which the most tedious numerical calculations
could not daunt, Kepler conjectured that the movemen