returns to the
same point in space from whence it started. This, however, is incorrect,
as we have to remember that the sun has also an orbital velocity of
18,000 miles per hour, so that while the earth has performed one
revolution in its orbit, the sun has actually progressed through space
to the extent of 18,000 x 24 x 365 = 157,680,000 miles.

When we come to deal with the sun's motion through space, we shall see
that this distance only represents a fraction of the sun's orbit, as it
can be philosophically proved, that if the sun moves at all, it, too,
obeys Kepler's Laws; and therefore, according to his First Law, it also
describes and possesses an orbit of its own. So that by the time the
earth has made its annual revolution round the sun, the whole system has
been carried 157,680,000 miles through space, and therefore the earth
does not complete a perfect ellipse, but its orbital motion round the
sun will be represented by a similar kind of diagram to the one which
represents the orbital motions of the moon, or any other satellite round
its central body.

ART. 106. _Eccentricity of Orbit of Moon._--From astronomical
observation we learn, that all the satellites and planets do not possess
uniformity of motion, as they are carried round their controlling
centres by the circulating aetherial currents, because the respective
controlling centres themselves move through space. The result is, that
the orbit of any satellite or planet is not always of the same size, but
constantly varies, sometimes having a larger circumference than at other
times, and sometimes a smaller circumference.

This change in the size of the orbit of a satellite or planet is known
as the eccentricity of the orbit, which eccentricity is constantly
changing, being sometimes greater and sometimes less. We will look at
this truth in its relation to the moon first, and then consider the same
principle in its relation to the earth and other planets later on. For
the purpose of illustration, we will consider the earth as being circled
round the sun by the electro-magnetic Aether currents in a closed orbit,
_A_ _B_ _C_ _D_, which forms a perfect ellipse, the sun occupying one of
the foci _S_ (Fig. 28), the earth occupying a position in the orbit
represented by point _C_, with the moon being circled round the earth by
that planet's aetherial currents. As we have already seen in Art. 103,
according to Kepler's Second Law, at this point the earth is f