365 days; then Mars in about 687 days then Jupiter with his four Moons in about 433 3 days; and laftly, Saturn in fomewhat above 10759 days, with his 5 or more Moons revolving about him. And beyond or above all these is the Firmament, or the Region of the Fixt Stars, which are all fupposed to be at equal diftances from their Center, the Sun. THIS is the Copernican Syfteme, which I have given a Scheme of in Fig. 2 And so far as this Syfteme relates to the Motion of the Earth, and the Sun refting in the Center, I prefer it to the Ptolemaick Hypothefis on thefe Five following accounts. 1. Because it is far more agreea ble to Nature, which never goes a round-about way, but always acts by the most compendious, easy and fimple methods. And in the Coper→ nican way, that is performed by one, or a few eafy Revolutions, which, in 2. the the other way, is made the work of the whole Heavens, and of many ftrange and unnatural Orbs. Thus the Diurnal Motion is accounted for by one Revolution of the Earth, which all the whole Heavens are called in for, in the other way; So for the Periodical Motions of the Pla news, their Stations, Retrogradations and Direct Motions, they are all accounted for by one eafy, fingle Motion round the Sun, for which, in the Ptolemaick way, they are forced to invent divers ftrange, unnatural, interfering Eccentricks and Epicycles. An Hypothefis fo bungling and monftrous, as gave occafion to a certain King to fay, If he had been of God's Council when he made the Heavens, he could have taught him how to have mended his Work. 2. As the Copernican is far more caly and agreeable to Nature than the Prolemaick Syfteme, so it is far more compleat 1 pleat, and anfwerable to the various Phænomena of the Planets feveral of which the Ptolemaick Hypothefts either very awkwardly folves, or dork not at all come up to. I might in ftance here in divers particulars rela ting to Venus and Mercury, as why the Earth is never between them and the Sun, which the Ptolemaick Syfteme gives no tolerable account of, and but poor accounts of other of their Phænomena, as alfo of thofe of the Moon and the other Planets. might fhew also how incoherent and improper the Motions affigned to the Heavenly Bodies are in the Ptolema ick way, as that the Moon fhould move round once in a Month, the other Planets in fuch and fuch Peri ods as are affigned to them; the Firm mament, or Fixt Stars in 25 or 26006 years, the Sphere beyond that in 1700 the Tenth Sphere, in 3400 and the outermoft of all, the years t years; Primum Primum Mobile, which moves all the reft in only 24 hours. Which are Motions fo unproportional and difagreeable, that are sufficient to fubvert the whole Hypothefis. But it would be endless to enter into a detail of fuch incoherences and improprieties as the Ptolemaick Syfteme abounds with. 3. The prodigious and inconceiv able Rapidity affign'd by the Ptolemaicks to the Heavens, is by the Coper nican Scheme taken off, and a far more eafy and tolerable Motion fub. ftituted in its room. For is it not a far more eafy Motion for the Earth to revolve round its own Axis in 24 hours, than for fo great a number of far mote maffy, and far diftant Globes, to revolve round the Earth in the fame space of time? If the Maintainers of the Ptolemaick Syfteme do object against the Motion of the Earth, that it would make us dizzy, and What a and shatter our Globe to pieces,what a precipitant, how terrible a Rapidity must that of the Heavens be a Velocity must the Sun have to run its course, at the diftance of 21 or 22 Semidiameters of the Earth What a Velocity muft that of the Fixt Stars, especially that of the Pri mum Mobile be, at far greater diftances than the Sun is ? Lat For 4. It is an incontestable argument of the Sun being the Center of the Planets about him, and not the Earth, that their Motions and Distances refpect the Sun, and not the Earth. with regard to the Sun, the Primary Planets have a very due Motion, in proportion to their feveral Distances that is, Their Motions round the Sun, are in fefquiplicate Proportion to their Distances from him: but this Proportion doth not hold at all with relation to the Earth. But as for the Secondary Planets, Found Saturn, 3 |