[25]. The utmost limit of a person’s view, where the Sky seems to touch the Earth all around, is called his Horizon; which shifts as the person changes his place.
[26]. The Plane of a Circle, or a thin circular Plate, being turned edgewise to the eye appears to be a straight line.
[27]. A Degree is the 360th part of a Circle.
[28]. Here we do not mean such a conjunction, as that the nearer Planet should hide all the rest from the observer’s sight; (for that would be impossible unless the intersections of all their Orbits were coincident, which they are not, See § [21].) but when they were all in a line crossing the standard Orbit at right Angles.
[29]. The Orrery fronting the Title-page.
[30]. To make the projectile force balance the gravitating power so exactly as that the body may move in a Circle, the projectile velocity of the body must be such as it would have acquired by gravity alone in falling through half the radius.
[31]. Astronomical Principles of Religion, p. 66.
[32]. Δὸς ποῦ στῶ, καὶ τὸν κόσμον κινήσω, i. e. Give me a place to stand on, and I shall move the Earth.
[33]. If the Sun was not agitated about the common center of gravity of the whole System, and the Planets did not act mutually upon one another, their Orbits would be elliptical, and the areas described by them would be exactly proportionate to the times of description § [153]. But observations prove that these areas are not in such exact proportion, and are most varied when the greatest number of Planets are in any particular quarter of the Heavens. When any two Planets are in conjunction, their mutual attractions, which tend to bring them nearer to one another, draws the inferior one a little farther from the Sun, and the superior one a little nearer to him; by which means, the figure of their Orbits is somewhat altered; but this alteration is too small to be discovered in several ages.
[34]. Religious Philosopher, Vol. III. page 65.