David Gregory

he understood, as it were by the Harmony of the Heavens, that the Gravity of the Planets towards the Sun (according to whose measures the Planets move) were reciprocally as the Squares of their Distances from the Sun.

Pythagoras... applied the proportion he had thus found by experiments, to the Heavens

[U]niversally, the Weights which generate all Tones in Strings, are reciprocally as the Squares of the lengths of Strings of equal Tension, producing the same sound in any Musical Instrument.

Pythagoras found out the true ratio between the sound of Strings and the Weights fasten'd to them.

are reciprocally as the Squares of the lengths of the Strings.

in the Harmonical ratio of their Distances. For the forces, whereby equal tensions act upon Strings of different lengths

they meant the Sun in Conjunction with the seven Planets, for they made him the leader of that Septenary Chorus, and Moderator of Nature; and thought that by his Attractive force he acted upon the Planets

Apollo playing upon an Harp of seven Strings, by which

he and his followers would signify to us by the Harmony of the Spheres: That is

[T]he famous Theorem about the proportion whereby Gravity decreases in receding from the Sun, was not unknown

For that Gravity is proportional to the Quantity of Matter in the heavy Body, Lucretius does sufficiently declare

Lucretius and those whom he followed, believ'd that all Bodies did Gravitate towards the Matter placed around them, and that every single Body was carried by the more prevailing Gravity, towards that region where there was most Matter.

during an infinite space of time, would have long ago met, and lye in the middle of the whole

by their Gravity, and therefore

make towards the inner and lower Bodies

the outmost Bodies, since they have no other beyond them

in the immense Space. His Argument

labours to prove, that the Universe

'Tis from this Doctrine of Gravity

[A]fterwards it diffused it self thro' the Italic Philosophy, the followers of which taught, that each Star was a World in the infinite Æthereal Space, containing Earth, Air and Æther; and that the Moon, not only was like our Earth, but …

These notions Anaximenes received from Anaximander, Anaximander from Thales himself, who was the Head and Founder of the Ionic Philosophy; and spread this opinion of the Gravity of the Fix'd Stars among his Sect.

That saying is well known, so often used by Anaxagoras, and his Scholars, Achelaus and Euripides, Namely, "That the Sun and Stars were fiery or red-hot Stones and Golden Clods." Of the same mind also were Democritus, Metrodorus, and …

[I]f we look back to the first Rise of Astronomy... we shall find nothing better approv'd of, nothing more universally entertained among the several Sects of Philosophers, than this notion of the Gravity of the Celestial Bodies.

[W]e do still tread in the steps of the Ancients in this Physical Astronomy; inasmuch as they knew that the Celestial Bodies gravitated towards each other, and were retain'd in their Orbits by the force of Gravity; and were also apprized …