ir The INTRODUCTION: 1

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It is proved in the fame Way, that Ju~ Apiter and Saturn have both the Sun and the . AEarth within their Orbits; and that the ;iSun, and not the Earth, is the Center of itheir Motions; altho’ the Disproportion of |the Distances from the Earth is not so great |in Jupiter as it is in Mars , nor so great in 1Saturn as it is in Jupiter , by reason that |they are at a much greater Distance from ;the Sun.

inferior We have now (hewn that all the Planetswf pf turn l'ound the Sun, and that Mercury andsets. Venus are included between him and theEarth; whence they are called the InferiorPlanets: And that the Earth is placed be-tween the Orbits of Mars and Venus, andtherefore included within the Orbits ofMars, Jupiter and Saturn', whence theyare called the Superior Planets: And sincethe Earth is in the Middle of these move-able Bodies, and is of the lame Nature withthem, we may conclude, that (he has thefame fort of Motions; but that (he turnsround the Sun, is proved thus:

The Earth All the Planets seen from the Earth ap-fndfiill, P ear to move very unequally; as sometimesh rLlTtL to S° ^ er > at other times (lower; some-sun. times to go backward, and sometimes tobe stationary, or not to move at all; whichcould not happen if the Earth stood still.

Let S be the Sun, T the Earth, the greatCircle ABCD the Orbit of Mars „ and

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