and our experience.

[Footnote 1: _Lectures on Scientific Subjects._]

ART. 25. _Kepler's Laws._--A long time before Newton had discovered the
Law of Gravitation, Kepler had found out that the motions of the planets
were governed by certain laws, and these came to be known as Kepler's
Laws.

These laws which were given to the world by Kepler, simply represented
facts or phenomena which had been discovered by observation, as Kepler
was unable to account for them, or to give any mathematical basis for
the same.

On the discovery, however, of Universal Gravitation, Newton saw at once
that these laws were simply the outcome of the application of the Law of
Gravitation to the planets, and that they could be accounted for on a
mathematical basis by the Law of Gravitation, as they seemed to flow
naturally from that law.

Kepler's Laws are three in number and may be thus stated--

_1st Law._ Each planet revolves round the sun in an elliptic orbit, with
the sun occupying one of the Foci.

_2nd Law._ In the revolution of a planet round the sun, the Radius Vector
describes equal areas in equal times.

_3rd Law._ The squares of the periodic times of planets are proportional
to the cubes of their mean distances.

Now the question arises, whether it is possible to form a theory of the
Aether which shall satisfactorily and philosophically account for all
the phenomena associated with Kepler's Laws in their relation to the
motions of planets, satellites, or other solar bodies? On the present
conception of the Aether such a result is an absolute impossibility.
With the theory of the Aether, however, to be submitted to the reader in
this work, the result is possible and attainable. If, therefore, such a
result is philosophically proved, as I submit will be done, then we
shall have greater evidence still that the theory so propounded is a
more perfect theory than the one at present recognized by scientists
generally.

ART. 26. _Kepler's First Law._--Each planet revolves round the sun in an
elliptic orbit, the sun occupying one of the Foci.

The ancients thought that the paths of the planets around the sun were
circular in form, because they held that circular motion was perfect. A
system of circular orbits for the paths of the planets round the sun
would be very simple in its conception, and would be full of beauty and
harmony. But exact calculations reveal to us that the path of a planet
is not exactly that of a circle,