must not be supposed that the Earth simply attracts "downward," that is, toward its centre. On the contrary, large masses of earth—large mountains, for instance—exert a certain degree of Attraction of Gravitation, and experiments have shown that a "plumb" is slightly deflected by reason of the proximity of a large mountain. And the reason that bodies "lose weight" as they descend from the surface of the earth is because they leave "above" them a certain large portion of the molecules composing the earth, which mass of molecules exert an attraction proportionate to their mass, which attraction balances the attraction of the mass of earth "beneath them."
Science teaches that if the earth were hollow in the centre, the weight there would be Zero, or nothing at all, and that a body would float in the space at the centre of the earth just as does a balloon in the air, the reason thereof being that the attraction would be equalized—equal attraction from every direction, counterbalancing each other. Considering the earth's radius to be 4000 miles, a body that weighed 100 pounds on the surface would weigh but 75 pounds at the depth of 1000 miles; but 50 pounds at a depth of 2000 miles; but 25 pounds at a depth of 3000 miles; and Nothing, or Zero, at a depth of 4000 miles, which would be the Centre of the Earth. This, of course, supposes that the Substance of which the earth is composed is of uniform density from surface to centre.
From an equal distance above the surface of the earth, bodies released, or dropped, will reach the surface at exactly the same degree of speed, and in exactly the same time—this irrespective of weight or size. In other words, a cork or piece of lead, no matter what their sizes may be, will travel with equal rapidity. In case where the "lighter" substance travels more slowly (compare a feather and bullet, for instance) the difference is caused by the light object meeting with more resistance from the air. This apparent exception has been explained away by the experiment of dropping the bullet and the feather in a vacuum tube, in which there was no resistance from air, the consequence being that both descended precisely at the same instant. Another similar experiment is to place the feather upon a piece of iron whereby the resistance of the air is prevented, and the feather will maintain its position during the drop, and will reach the ground resting on top of the iron, just as it started.
And, remember this please, that the small object attracted by the earth exerts an attraction on its own account. If the two were of the same size they would exert an equal attracting power, but as one is smaller its attracting power is very slight compared with that of the large mass. But it is true that the particle of dust attracts the earth precisely as the earth attracts the particle of dust—the difference being solely a matter of degree depending upon the "mass" of the body. The amount or degree of the combined attracting power is determined by the combined total of the two masses. Distance lessens the degree of attraction—thus as bodies are lifted above the earth the weight decreases very gradually, and by very slight degrees, but constantly and invariably. The poles of the earth are flattened, and, consequently, the weight of an object slightly increases as it is carried from equator to pole.
Concluding our consideration of Gravitation, it will be well to call your attention to the fact that Gravitation differs from the forms of Radiant Energy known as Heat, Light, Electricity and Magnetism in several very important particulars, which seems to go far in the direction of proof that the latter are by incidents or consequences of the former.
In the first place, Gravitation, so far as is known, is not dependent upon, caused by, or maintained by, any other Force or form of Energy. Nor does it seem to be derived from some great reservoir, from which it obtains its supply of Energy. On the contrary, it seems to be a "thing-in-itself," self-supporting, self-existing—an intrinsic thing, in fact. It does not seem to be lost to bodies by radiation. And consequently there seems to be no need of a body replenishing its supply, as there is no loss. Gravitation seems to be a constant something, remaining always with bodies and neither being lost or acquired. It exists between the Atoms, Molecules, Masses—all in the same way. In fact, one is tempted to think of the planets and worlds in space, as Molecules of some greater Mass held together by Gravitation just as are the Molecules held together. Remember, that the Molecules and Atoms are not in absolute contact, but there is always a "space" between them, although the space or distance may be "insensible" to us. "As above, so below," says the old occult aphorism, and it seems to be so.
Then again, Gravitation is believed to act instantaneously, and does not require Time to pass between bodies, as does Light, Heat, Electricity, Magnetism—Radiant Energy. Light travels through the Ether (as light-waves) at the rate of 184,000 miles a second. The same is true of Heat and of Electricity. But Gravitation travels instantaneously. For instance, if a new star were to spring into existence at some inconceivable distance from the earth it would require thousands of years for its light to reach us. But its Attraction of Gravitation would be felt instantly. Do you realize what this means? It means that Gravitation is in some way connected with the Ether, or "conveying medium," that an impulse communicated at some point of space trillions of miles away is felt at once at our point in space, and vice versa. There is some awful mystery here, and the laws of Substance, and Force, as generally understood, do not account for it. And the theories regarding the Ether do not throw light upon it. But wait a bit!
But more than this. Science holds that Gravitation does not require a medium—that it seems to be its own medium—needing no "Ether" or other medium to transmit its influence. In this respect also, Gravitation differs from the form of Radiant Energy. And more, it is not "cut-off" or interfered with by any intervening body, for its force operates through such intervening bodies. For instance, in an eclipse of the Sun, the Moon passes between the Earth and the Sun, but the Gravitation is not affected in the slightest, for the bodies would evidence such change immediately were it to occur.
So Gravitation acts instantaneously; is its own medium, and may not be interfered with by an intervening body. It, indeed, is in a different "class" from Light, Heat and Electricity.
And now let us consider the other forms of Attraction.
In the previous chapters we saw that the form of Attraction called "Cohesion" caused the molecules to tend to each other, and to remain in more or less close contact, the differing degrees of Cohesion determining the Density, etc., of the body. Were the Attractive force of Cohesion suddenly removed, the most solid bodies, as well as the lightest ones, would instantly fly into very fine powder, thus being resolved into their constituent molecules. The separation of the Molecules, that is, the "setting further apart," occasioned by Heat, is spoken of by Physicists as "Repulsion." But the writer holds that repulsion is an entirely different thing, and that the heat merely causes the Molecules to lose a portion of their Attractive power for each other. Until the heat being withdrawn, the Molecules respond to the uninterrupted Attraction. The Molecules are like lovers who are attracted toward each other, and remain attached unless separated violently, or by some fading of Attraction. Consider Heat as a disturbing element—a "misunderstanding" between the molecular lovers, who under its influence draw somewhat apart, and are only reunited when the obstacle is removed, and harmony again manifested.
As we have shown you in a previous chapter, the so-called "properties" of Matter, i.e., Hardness, Tenacity, Malleability, Ductility, etc., are simply evidence of a persistent Cohesiveness of the Molecules—a strong "love" or "desire" for each other that caused them to adopt every possible means in their power to resist, and prevent, the separation of the Molecules forming the mass. It was like a desperate attempt to prevent the "breaking up of the family."
Each so-called Special Physical Property of Matter is seen to be but the action of the Molecule resisting separation, in obedience to that law of its being called "Attraction," or "Gravitation," or "Cohesion," or "Adhesion"—but which might as fitly be called "Desire," or "Love." And, remember, that this law does not seem to be merely one of self-preservation of the Molecule—for it remains intact even after the separation from its companions or family. It is more, for it is a law that causes it to bend all its energies in remaining within "molecular distance" or close companionship with its family, and resisting disintegration. It is like the "social instinct" in Man, if one may be pardoned from using the figure.
Now for the Attraction of the Atoms—"Chemical Affinity," or "Chemism," as it is called. An Atom, you know, is the chemical unit of Matter, and the smallest particle of Matter that can