urface of the earth, that is exactly double the
distance from the centre of the earth, the radius of the earth being
approximately 4000 miles. According to the law of inverse squares, the
force of Gravitation decreases inversely as the square of the distance.
The distance having been doubled, the proportion of the forces at the
two places, _i. e._ the earth's surface and 4000 miles above it, are as
1 to 1/4.

Thus at a distance of 4000 miles the weight which weighed one pound at
the earth's surface, now only weighs a quarter of a pound. At a distance
of 8000 miles, the distance would be trebled, therefore the force of
Gravitation is one-ninth, and the weight would weigh one-ninth of a
pound. If we could take the pound weight to the moon, the attractive
force of the earth would be reduced to 1-3600, as the moon is 240,000
miles distant, that is sixty times the earth's radius. The square of 60
is 3600, and if we invert that we get 1-3600, so that the weight which
weighs a pound at the earth's surface, would only weigh 1-3600 part of a
pound at the distance of the moon. This again proves, that apart from
the Attraction of Gravitation, there is no such thing as weight, and
that the weight so called of any body, such as a planet or satellite,
increases or decreases as its distance increases or decreases from its
central attracting body.

ART. 24. _Centrifugal Force._--I have already shown in Art. 10 that
the Centripetal Force and Universal Attraction are one and the same; as
the Centripetal Force always acts towards the centre, and must therefore
be in its operation and influence a gravitating or attractive power.

I have also pointed out in the same article, the necessity of another
force, which is to be the complement, and the counter part of
Gravitation Attraction. That complement and counter force was conceived
by Newton, and called by him the Centrifugal Force. The very nature of
the Centripetal Force demands and necessitates a force which in its mode
of operation is exactly the opposite of the Centripetal Force. Unless
there were such a force, a repellent and repulsive force, then instead
of there being that harmonious working of the universe that now exists,
there must inevitably be a gradual drawing together of all planets and
satellites, of all stars and suns, into one vast, solitary, and ruinous
body.

There are also other phenomena which demand a Centrifugal Force in the
universe. It is a well-known fact, th