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HISTORY O 1' ASTRONOMY*

The Stars, when more attentively furvc-yed,were home of them observed to be lefs coni laneand uniform in their motions than the reft, and tochange their situations with regard to the otherheavenly bodies; moving generally eaftwards, yetappearing sometimes to ftand ftill, and sometimeseven to move westwards. These, to the numberof five, were diftinguilhed by the name of Planets ,or wandering Stars , and marked with the parti-cular appellations of Saturn , Jupiter > Mars , Ve­ nus , and Mercury. As, like the Sun and Moon,they feem to accompany the motion of the Fixed Stars from eaft to welt, but at the fame time tohave a motion of their own, which is generallyfrom weft to eaft; they were each of them, as wellas thole two great lamps of heaven, apprehendedto be attached to the infide of a iblid concave andtranlparent Iphere, which had a revolution of itsown , that was almoft diredtly contrary to the re-volution of the outer heaven , but which, at thefame time, was hurried along by the superiorviolence and rapidity of this half.

Tills is the fyftem of concentric Spheres, diehill regular fyftem of Aftronomy, which theworld beheld, as it was taught in the Italianschool before Ariftotle and his two cotemporaryphilosophers, Fudoxus and Callippus , had givenit all the perfeilion which it is capable of recei-ving. Though rude and inartificial, it is capableof connecting together, in the imagination, thegrandeft and the mo ft seemingly disjointed appear-ances in the heavens. The motions of the moll