Autumn, third season of the year, harvest time of the fruits of summer. See Season, Year, etc.

Some say it comes from augeo , I increase, quod annum frugibus augeat . [1]

Autumn begins the day that the meridian distance of the sun to the zenith, after having decreased, finds itself midway between the greatest and the least. The end of autumn meets the beginning of winter. During autumn the days go by while growing shorter, and are always shorter than the nights, except the first day of autumn, which is the day of the equinox. See Winter, etc.

Diverse nations have counted the years by the autumns, like the Anglo-Saxons by the winters. Tacitus teaches us that the ancient Germans knew all the seasons of the year except autumn, of which they had no idea.

It has always been thought that autumn was an unhealthy season. Tertullian calls it tentator valetudinum . [2] Horace also says, autumnus libitinae quaestus acerbae . [3]

Autumn equinox is the time when the sun enters the autumnal point. See Autumnal.

Notes

1. "because it augments the year with fruits." I could not find the exact Latin source from which D’Alembert is quoting here. The word “quod” was especially tricky to me due to its various meanings depending on its position in a given line or sentence. Professor IML Donaldson kindly translated this Latin phrase and provided an explanation of the word “quod,” which, he explains, translates here to because since that would make D’Alembert’s sentence grammatically coherent by linking the first clause in French to the Latin phrase. Professor Donaldson also suggests referring to the Oxford English Dictionary under “autumn” (there is an online version, <www.oed.com>, but I did not view this word); and A Latin Dictionary , Charlton T. Lewis and Charles Short, under “auctumnus (autumnus),” for more discussion of the words “autumn” and “autumnus,” http://www.perseus.tufts.edu/hopper/morph?l=auctumnus&la=la&can=auctumnus0#lexicon.]

2. "The tryer of health." Tertullian writes, “As to the seasons of the year, dreams are calmer in spring, since summer relaxes, and winter somehow hardens, the soul; while autumn, which in other respects is trying to health , is apt to enervate the soul by the lusciousness of its fruits.” (My italics.) From Early Church Fathers: The Writings of the Fathers Down to A.D. 325, Ante-Nicene Fathers, Vol. 3, Latin Christianity: Its Founder, Tertullian, Part First: Apologetic, (IX): A Treatise on the Soul , Ch. 48 (XLVIII): “Causes and Circumstances of Dreams. What Best Contributes to Efficient Dreaming,” Peter Holmes, D.D., trans., edited by Allan Menzies, D.D. (Edinburgh: T&T Clark, no date given), http://www.ccel.org/ccel/schaff/anf03.txt (accessed Nov. 5, 2012). This Vol. 3 is part of a 10-volume set edited by Philip Schaff and Allan Menzies (Grand Rapids, MI: Wm. B. Eerdmans Publishing Co., the “ccel.org” Website states that these volumes of the Ante-Nicene Fathers were originally printed in 1885). A portion of the original Latin text from Tertullian’s Quae Supersunt Omnia, “ De Anima” (p. 633), which includes the quoted material in D’Alembert’s article, reads: “Ex temporibus autem anni verno magis quieta, quod aestas dissolvat animas et hiems quodammodo obduret, et autumnus, temptator alias valetudinum , sucis pomorum vinosissimis diluat.” (My italics.) Tertulliani, “De Anima,” Continens Libros Polemicos et Dogmaticos, Quae Supersunt Omnia, Franciscus Oehler, Ed., Vol. 2 (Lipsiae: T.O. Weigel, 1853): 633, http://babel.hathitrust.org (accessed Nov. 1, 2012).]

3. "... autumn, that brings gain to hateful Libitina." The lines from the Latin are: “Ergo ubi me in montes et in arcem ex urbe removi,/quid pruis illustrem saturis Musaque pedestri? / nec mala me ambitio perdit nec plumbeus Auster / autumnusque gravis, Libitinae quaestus acerbae ” (16-19) (My italics). [“So, now that from the city I have taken myself off to my castle in the hills, to what should I sooner give renown in the Satires of my prosaic Muse? Here no wretched place-hunting worries me to death, nor the leaden scirocco, nor sickly autumn, that brings gain to hateful Libitina ” (My italics)]. In ancient Rome, Libitina was the goddess of funerals. Horace: Satires, Epistles, and Ars Poetica , Book II, Satire VI, Tr. H. Rushton Fairclough, The Loeb Classical Library, Vol. LCL 194, pp. 210-211, Founded by James Loeb, LL.D.; Eds. T.E. Page, E. Capps, W.H.D. Rouse, L.A. Post, E.H. Warmington (London: William Heinemann, Ltd.; Cambridge, MA: Harvard Univ. Press; first printed 1926, revised and reprinted 1929, reprinted 1932, 1936, 1939, 1942, 1947), http://babel.hathitrust.org (accessed October 31, 2012).

Note : Prof. Donaldson ( see Fn. 1, above) noticed that a few typos were generated in the scanned version of D’Alembert’s Encyclopédie article where the letters ae in the Latin words Libitinae quaestus acerbae from Horace’s quoted verse were inadvertently transformed to oe .]