Text: The force as, or that of gravitation, has, since the time of Sir Isaac Newton, been recognized as one of the forces affecting a planet, compelling it to the completion of the path of its orbit. The path of the orbit, then, necessarily results from the action of this with some other force, and this latter force, from the consideration in Section III, must, at every point of that path, be equal to the force of gravitation; from whence it results that the continuing pathway of the orbit of the planet can result only from a continuing and relative change of position of these equal and opposed forces, one toward the other. Now, the diagram of the ultimate effect of the exertion of these forces for any one point of the path of the planet's orbit, Section IV, must be that for every other point, as least, for that portion of the orbit between the higher and lower vertices of the ellipse; from whence it follows, that for every point, at least between those vertices, the planet is subjected to the action of remnant and directly opposed forces exerted in direction of right line connecting the center of the planet with the immovable center of force. One effect of the exertion of such remnant forces may be mechanical, forcibly holding the planet in position: another effect, also mechanical, may be that of pressure.

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Source: 159