They seemed to defy the laws of gravitation in walking over the rim rock; for, instead of tumbling headlong as I feared, they went skidding downward, bouncing, side-stepping, twisting and angling across the wall like coasters on snow; they could not stop their downward drop, but they controlled their descent by making brakes of their feet, and taking advantage of every small bump to retard their speed.

Does the attraction for both of them follow the same law as to distance as is given by the planetary motions round the sun? It has been stated that in this way the first conception of universal gravitation arose.

It is needful now to look at the other term in the product we call energy, namely, the substance moving, sometimes called matter or mass. It has been mentioned that the idea of a medium filling space was present to Newton, but his gravitation problem did not require that he should consider other factors than masses and distances.

This assumption is necessary because gravitation takes no account of mere corporeal bulk, but only of mass or ultimate solidarity. Thus a very bulky object may be so closely meshed that it retards relatively few of the corpuscles, and hence gravitates with relative feebleness or, to adopt a more familiar mode of expression, is light in weight.

The fact was that Newton had not only to construct the theory of gravitation, but he had to invent the mathematical tools, so to speak, by which his theory could be applied to the explanation of the movements of the heavenly bodies. In the course of the century which had elapsed between the time of Newton and the time of Laplace, mathematics had been extensively developed.

Referring to the conceivable causes of unlike specific gravities in the members of the solar system, it was said that these might be Differences between the kinds of matter or matters composing them. 2. Differences between the quantities of matter; for, other things equal, the mutual gravitation of atoms will make a large mass denser than a small one. 3.

Hartley had worked out the theory of association of ideas which Hume had already compared to the universal principle of gravitation in the physical world; and had endeavoured to show how this might be connected with physiological principles. Hartley's followers had been content to dwell upon the power of association.

Men and women marry for flesh or gold, they put half their whole into the contract, and their sacrilegious bargain smites them with a curse. It is the law of compensation, the workings of that moral gravitation which causes all things to fit into their own places, and is to us the clearest indication of the workings of the Divine in all this tumultuous life.

As soon as the outbursts are over, and the scattered particles have reached the farthest limit to which they are hurled, the concentrating action of gravitation will slowly assert itself. If we conceive this gravitational influence as the pressure of the surrounding ether we get a wider understanding of the process.

Bear in mind that the true theory of life, whenever it shall be reached in human conception and formulated into definitely-known processes of action, must satisfactorily explain all life-manifestations, as Newton's theory of gravitation accounts for the movements of all celestial bodies.