95. THE SOLAR SYSTEM here described is not a late invention; for it was known and taught by the wise _Samian_ philosopher PYTHAGORAS, and others among the ancients; but in latter times was lost, ’till the 15th century, when it was again restored by the famous _Polish_ philosopher NICHOLAUS COPERNICUS, who was born at _Thorn_ in the year 1473. In this, he was followed by the greatest mathematicians and philosophers that have since lived; as KEPLER, GALILEO, DESCARTES, GASSENDUS, and Sir ISAAC NEWTON; the last of whom has established this System on such an everlasting foundation of mathematical and physical demonstration, as can never be shaken: and none who understand him can hesitate about it. [Sidenote: The Ptolemean System absurd.] 96. In the _Ptolemean System_ the Earth was supposed to be fixed in the Center of the Universe; and that the Moon, Mercury, Venus, the Sun, Mars, Jupiter, and Saturn moved round the Earth: above the Planets, this Hypothesis placed the Firmament of Stars, and then the two Crystalline Spheres; all which were included in and received motion from the _Primum Mobile_, which constantly revolved about the Earth in 24 hours, from East to West. But as this rude Scheme was found incapable to stand the test of art and observation, it was soon rejected by all true philosophers; notwithstanding the opposition and violence of blind and zealous bigots. [Sidenote: The Tychonic System, partly true and partly false.] 97. The _Tychonic System_ succeeded the _Ptolemean_, but was never so generally received. In this the Earth was supposed to stand still in the Center of the Universe or Firmament of Stars, and the Sun to revolve about it every 24 hours; the Planets, Mercury, Venus, Mars, Jupiter, and Saturn, going round the Sun in the times already mentioned. But some of TYCHO’s disciples supposed the Earth to have a diurnal motion round it’s Axis, and the Sun with all the above Planets to go round the Earth in a year; the Planets moving round the Sun in the foresaid times. This hypothesis, being partly true and partly false, was embraced by few; and soon gave way to the only true and rational System, restored by COPERNICUS and demonstrated by Sir ISAAC NEWTON. 98. To bring the foregoing particulars at once in view, with several others which follow, concerning the Periods, Distances, Bulks, _&c._ of the Planets, the following Table is inserted. A TABLE Of the PERIODS, REVOLUTIONS, MAGNITUDES, &c. of the PLANETS.