xperiment, if men would only follow their indications, are consistently
enforcing the necessity of erasing these antiquated chimeras from the
book of knowledge; and inculcating the great truth, that the physical
universe owes all its endless variety to differences in the form, size,
and density of planetary atoms in motion, according to simple mechanical
principles. These, combined with the existence of an all-pervading
medium filling space, between which and planetary matter no bond of
union subsists, other than that which arises from a continual
interchange of motion, are the materials from which the gems of nature
are elaborated. But, simplicity of means is what philosophy has ever
been reluctant to admit, preferring rather the occult and obscure.

If action be equal to reaction, and all nature be vibrating with motion,
these motions must necessarily interfere, and some effect should be
produced. A body radiating its motion on every side into a physical
medium, produces waves. These waves are a mechanical effect, and the
body parts with some of its motion in producing them; but, should
another body be placed in juxtaposition, having the same motion, the
opposing waves neutralize each other, and the bodies lose no motion from
their contiguous sides, and, therefore, the reaction from the opposite
sides acts as a propelling power, and the bodies approach, or tend to
approach each other. If one body be of double the inertia, it moves only
half as far as the first; then, seeing that this atomic motion is
radiated, the law of force must be directly as the mass, and inversely
as the squares of the distances. There may be other atomic vibrations
besides those which we call light, heat, and chemical action, yet the
joint effect of all is infinitesimally small, when we disregard the
united _attraction_ of all the atoms of which the earth is composed. The
_attraction_ of the whole earth at the surface causes bodies to fall 16
feet the first second of time; but, if two spheres of ice of one foot
diameter, were placed in an infinite space, uninfluenced by other
matter, and only 16 feet apart, they would require nearly 10,000 years
to fall together by virtue of their mutual attraction. Our conceptions,
or, rather, our misconceptions, concerning the force of gravity, arises
from our forgetting that every pound of matter on the earth contributes
its share of the force which, in the aggregate, is so powerful. Hence,
the cause we have