[Margin: Turriano’s eulogy, from [the pen of] Astronomy.]

[I.] I will begin from the Epistle which Girolamo Fracastoro of Verona—eminent in the ornaments of Astronomy, Medicine, and Poetry—wrote to Pope Paul III, that he might dedicate to him his Homocentrica. In which, among other [things], he affirms that Philosophy—nay, nature itself, and the celestial orbs themselves—always cried out against the Eccentrics and Epicycles of Hipparchus and Ptolemy; and that therefore many had striven, but with vain labor, to explain the causes of the celestial motions by another way. Then he thus narrates: “In our age, Giovanni Battista Turriano, our [fellow-]citizen—a man of the greatest and almost divine genius, and a cultivator of a certain more secret Philosophy—discovered two admirable motions in the spheres: those (as I think) which both Albategnius and most other Astronomers prophesied to lie hidden in the stars; through which he seemed to himself to have gained an approach to explaining many things, but especially to demonstrating, without any Eccentrics, those [phenomena] which are seen about the stars. Which matter he had begun to turn over in [his] mind with great hope; when—fortune deciding otherwise (better had he said, God)—at the very beginnings he was forestalled by an immature and unexpected death: a youth most flourishing and admirable in age, genius, studies, virtue, and every discipline. And when he was now about to die (just as they relate that the thrice-great Mercury [Trismegistus], dying, asked the friends standing by to be mindful of that ship which he had taught perpetually to ascend and descend in the midst of the ether), so he, turned to us friends who stood by, when he had said many other things, then, looking at me, said: ‘I have something, Fracastoro, which I ask of you as [my] last [request].’ And when I urged him to speak: ‘I would wish you,’ he said, ‘to be mindful of those circles which Timaeus first cuts into the figure of the letter X, then so twists back that the heads of the lines come together among themselves’ (he meant the motions discovered by him); ‘then, because death now envies me [this], if I might hope that you would accomplish [it], and that the business, grasped by me, would be perfected—it will be a great consolation to me, [now] dying.’ To whom I [answered] that I would be mindful, etc.”

[Margin: Fracastoro, a reviver of the Homocentrics.]

[II.] This, then, was the occasion for Fracastoro of thinking out in what way he could explain all the celestial motions by homocentric orbs alone—that is, concentric with the center of the world. But because, to accomplish this, it was necessary to give a reason why the Moon and the other Planets appear sometimes larger, sometimes smaller than themselves—since he could refer this neither to the Eccentrics nor to the Epicycles, as [they were] eliminated from his hypothesis—he tried (sect. 1, ch. 8, & sect. 3, ch. 23, [in chapters] which are entitled “On the diversity of aspect [parallax] in the quadratures, and in the swift and slow motion”) to refer the cause to a diversity of the medium: if not of the air, at least of the heaven [which is] somewhere rarer, somewhere denser—the heaven, I say, subject to the Moon, which is so moved that, whenever the Moon is in the quadratures, on account of the refraction of the Solar rays, in the denser but transparent part of that Zone which glides between the Zodiac and the Moon, it exhibits its disc larger than usual as to appearance. But this otherwise so great a man does not seem to have understood what that diversity of aspect [parallax] is, from which Ptolemy shows the diversity of the Lunar distance from the earth; for this is not merely a difference of apparent magnitude, but a difference between the true place and [the place] seen by us from the surface of the earth—[a thing] often set forth by us, but especially [in] bk. 1, ch. 35, and bk. 3, ch. 7, and bk. 4, ch. 13 & 14. Which last places being reread, it will be evident that the difference of the Lunar parallaxes is so great, and such, that its cause cannot be poured back upon the Fracastorian refraction; nor upon the nearness of a greater light, which is the other cause adduced by him. Moreover, Fracastoro supposes the Ptolemaic order of the Planets. Finally, he devises very many Homocentrics, by whose aid the inequality of the proper motion of the Fixed [stars] and Planets may come about—which, briefly, though useless, I shall enumerate.

[Margin: The orbs of the Aplanes [non-wandering sphere] — 7.]

[III.] First, then, for the Aplanes, or sphere of the non-wandering [stars] (sect. 2, ch. 17), he employs 7 orbs. The first and supreme is the Prime Mobile, carrying with it all the lower [orbs], whose most simple motion of 24 hours is made from Rising to Setting through the Equator. The second is the Circumducens [Around-leader], which—carried in latitude through the higher colure from North to South in 3600 years—rolls with it all the lower orbs, except in so far as some counter-carried [orbs] impede it; the circle of whose motion cuts the Equator at right angles and has its Poles in the Equator. The third is the Circitor [Circler], whose circle, subaltern to the lower colure of the Equinoxes, is led around in latitude by the higher circle in 3600 years, but of itself moves all [things] in the opposite direction, and completes 4 degrees in that time in which the Circumducens completes a quarter of its circle. The fourth orb is called Contravectus [Counter-carried] to the Circitor and the Circumducens in latitude, which, through the higher colure—twice as swift as the Circumducens—is carried from South to North. The fifth is the Anticircitor [Anti-circler], which is rolled by the fourth in latitude, always in the direction opposite to the Circitor, and proportionally; whence it comes about that, by its proper motion, it is always opposed to the Circitor in latitude, but agrees [with it] in longitude, and drives [it] into the same [direction]. But lest the Aplanes be moved in latitude—that is, lest the fixed [stars] vary [their] latitude—the Contravectus follows the Anticircitor, which prevents this motion. Lastly, and in the seventh place, is the Aplanes, or the very sphere of the fixed [stars], which of itself, by [its] mean motion, completes one degree in 100 years, but per accidens now more quickly, now more slowly—the period of which inequality is completed in 3600 years.

[Margin: The orbs of the Planets.]

[IV.] But to Saturn Fracastoro attributes 10 orbs (sect. 2, ch. 21); and to Jupiter 11 orbs (ch. 24); and to Mars 9 (ch. 27); but in sect. 3, ch. 10, he gives the Sun 6 orbs, or at least 4; and (ch. 15) to Venus 11 orbs; and (ch. 19) to Mercu—

[…continues on p. 287 (PDF 322): “…ry…” — the remaining homocentric orb-counts (Mercury, the Moon), the total, and Riccioli’s appraisal of the Fracastorian system before the next world-system.]

(printed p. 287 — Chapter VII concludes with Fracastoro’s orb-counts and a table of Fracastorian orbs. Chapter VIII then opens, on the Tychonic system of Tycho, Longomontanus, Blancanus, and many Tychonics, including the System IV diagram, the Ursus plagiarism dispute, and the Tychonic/Copernican concordance. A large engraved diagram of the Tychonic system fills the right column.)

…[and, ch. 19, to] Mercury, 11 orbs; finally (ch. 24) he assigns to the Moon 7 orbs. Which orbs he names Circitores, Circumducentes, Contravecti, Anticircitores, etc.; to which he adds 7 orbs carrying the bodies of the Planets. Nor is there need to shake out the superfluous furniture of this farrago of solid orbs—since we have already rejected solid orbs (sect. 1, ch. 7), and have confirmed the variation of the distances from the earth in each Planet by far stronger arguments (bk. 7, sect. 6, ch. 1). Wherefore, only for the sake of a little erudition, it is enough to know that the sum of the Fracastorian homocentric orbs ascends to the number 77 or 79; but if you number the starless orbs, Scheiner rightly said [it] to be 70, or at least 72, as is clear from the following little-table.

THE FRACASTORIAN ORBS