Attestantur autem quae fiunt dictis. Quia enim continue quidem, magis autem et minus, et maior et minor fit exhalatio, semper nubes fiunt et spiritus, secundum tempus unumquodque, ut nata sunt. Quia autem aliquando quidem vaporosa fit multiplicior, aliquando autem sicca et fumosa, quandoque quidem pluviosi anni fiunt et humidi, quandoque autem ventosi et sicci. Aliquando quidem igitur accidit et siccitates et imbres multos simul et secundum continuam fieri regionem: aliquando autem secundum partes. Saepe enim quae in circuitu regio, accipit temporaneos imbres et multos, in aliqua autem parte huius siccitas est: aliquando autem contrarium, ea quae in circuitu omni aut mediocriter utente aquis, aut et magis sicca, una aliqua pars aquae copiosam accipit multitudinem. Causa autem quia ut secundum plurimum quidem, eandem passionem ad plurimam pertingere verisimile regionem, quia similiter ponuntur ad solem quae prope; nisi aliquid differens habeant proprium. Quinimmo aliquando secundum hanc quidem partem sicca exhalatio facta est amplior, secundum aliam autem vaporosa: aliquando autem contrarium. Et ipsius autem huius causa, quia utraque transcendit in habitae regionis exhalationem: puta sicca quidem secundum propriam regionem fluit, quae autem humida, ad vicinam, aut et in aliquem remotorum locorum propulsa est a spiritibus; aliquando autem haec quidem mansit, contraria autem idem fecit. Et accidit hoc saepe, sicut in corpore animalium si superior ventus siccus fuerit, inferior autem contrarie disponatur, et hoc sicco existente, humidum esse superiorem et frigidum, sic et circa loca antiperistasim pati et permutari exhalationes. The facts bear out our theory. It is because the evaporation takes place uninterruptedly but differs in degree and quantity that clouds and winds appear in their natural proportion according to the season; and it is because there is now a great excess of the vaporous, now of the dry and smoky exhalation, that some years are rainy and wet, others windy and dry. Sometimes there is much drought or rain, and it prevails over a great and continuous stretch of country. At other times it is local; the surrounding country often getting seasonable or even excessive rains while there is drought in a certain part; or, contrariwise, all the surrounding country gets little or even no rain while a certain part gets rain in abundance. The reason for all this is that while the same affection is generally apt to prevail over a considerable district because adjacent places (unless there is something special to differentiate them) stand in the same relation to the sun, yet on occasion the dry evaporation will prevail in one part and the moist in another, or conversely. Again the reason for this latter is that each evaporation goes over to that of the neighboring district: for instance, the dry evaporation circulates in its own place while the moist migrates to the next district or is even driven by winds to some distant place: or else the moist evaporation remains and the dry moves away. Just as in the case of the body when the stomach is dry the lower belly is often in the contrary state, and when it is dry the stomach is moist and cold, so it often happens that the evaporations reciprocally take one another's place and interchange. Adhuc autem post imbres ventus, ut secundum multa, fit in illis locis secundum quae contigerit fuisse imbres: et spiritus cessant, aqua facta. Hoc enim necesse accidere propter dicta principia. Cum enim pluerit, terra desiccata ab eo quod in ipsa calido et ab eo quod desuper, exhalat; hoc autem erat venti corpus. Et cum talis segregatio fuerit, et venti obtineant, cessantibusque quia segregatur calidum semper et sursum fertur in superiorem locum, constat vapor infrigidatus, et fit aqua. Et cum in idem compellantur nubes, et contra circumsteterit ad ipsas frigiditas, fit aqua et infrigidat siccam exhalationem. Cessare igitur faciunt factae aquae ventos, et cessantibus, ipsae fiunt, propter has causas. Further, after rain wind generally rises in those places where the rain fell, and when rain has come on the wind ceases. These are necessary effects of the principles we have explained. After rain the earth is being dried by its own heat and that from above and gives off the evaporation which we saw to be the material cause of. wind. Again, suppose this secretion is present and wind prevails; the heat is continually being thrown off, rising to the upper region, and so the wind ceases; then the fall in temperature makes vapor form and condense into water. Water also forms and cools the dry evaporation when the clouds are driven together and the cold concentrated in them. These are the causes that make wind cease on the advent of rain, and rain fall on the cessation of wind. Adhuc autem fiendi maxime spiritus ab Ursa et meridie, eadem causa: plurimi enim boreae et austri fiunt ventorum. Sol enim sola haec loca non supergreditur, sed ad haec: et ab his super occasus autem et super orientes semper fertur. Propter quod nubes consistunt in lateralibus; et fit, accedente quidem, exhalatio humidi, abscedente autem ad contrarium locum, aquae et hiemes. Propter lationem quidem igitur quae ad tropicos et a tropicis, aestas fit et hiems, et elevatur sursum aqua, et fit iterum. Quoniam autem plurima descendit aqua quidem in his locis in quibus vertitur et a quibus; haec autem sunt quae ad arctum et meridiem ; ubi autem plurimam aquam terra suscipit, hic plurimam necessarium fieri exhalationem, simili modo ut ex viridibus lignis fumum; exhalatio autem haec ventus est: rationabiliter utique hinc fient plurimi et principalissimi spirituum. Vocantur autem qui quidem ab arcto, boreae: qui autem a meridie, austri. The cause of the predominance of winds from the north and from the south is the same. (Most winds, as a matter of fact, are north winds or south winds.) These are the only regions which the sun does not visit: it approaches them and recedes from them, but its course is always over the west and the east. Hence clouds collect on either side, and when the sun approaches it provokes the moist evaporation, and when it recedes to the opposite side there are storms and rain. So summer and winter are due to the sun's motion to and from the solstices, and water ascends and falls again for the same reason. Now since most rain falls in those regions towards which and from which the sun turns and these are the north and the south, and since most evaporation must take place where there is the greatest rainfall, just as green wood gives most smoke, and since this evaporation is wind, it is natural that the most and most important winds should come from these quarters. (The winds from the north are called Boreae, those from the south Noti.) 178. Postquam Philosophus determinavit de mari, cuius salsedo causatur ex admixtione exhalationis siccae terrestris, consequenter determinat de ventis, qui ab eadem exhalatione sicca causantur. Et dividitur in partes duas: 178. After determining about the sea, whose saltiness is caused from an admixture of the dry earthy exhalation, the Philosopher subsequently determines about the winds, which are caused by the same dry exhalation. And it is divided into two sections: in prima determinat de ipsis ventis; in the first he determines about the winds themselves, at (358a27); in secunda de quibusdam passionibus ex ventis causatis, ibi: de agitatione autem et motu et cetera. in the second about certain phenomena caused from winds at we must go on to discuss earthquakes next (365a14). Prima iterum dividitur in duas: The first is divided into two parts: in prima determinat de ventis in communi; in the first he determines about winds in general; in secunda de speciebus ventorum, ibi: de positione et cetera. in the second about the species of winds at let us now explain the position of the winds (363a21). Prima dividitur in tres partes: The first is divided into three parts: in prima determinat de generatione ventorum; in the first he determines about the generation of winds, at (358a27); in secunda de motu locali eorum, ibi: latio autem ipsorum etc.; in the second about their local motion at the course of winds is oblique (361a22); in tertia de augmento et quietatione ipsorum, ibi: sol autem et cessare et cetera. in the third about their increase and abatement at the sun both checks the formation of winds (361b14). Circa primum tria facit: Regarding the first he does three things: primo praemittit principia generationis ventorum; first, he lays down the principles of the generation of winds (358a27); secundo ponit modum generationis eorum, ibi: exhalatione autem sicut etc.; second, he describes the manner of their generation, at consequently, since there are two kinds of evaporation (360a8); tertio manifestat quod dictum est, ibi: hoc autem quod isto modo et cetera. third, he manifests what has been said, at that things must necessarily take this course (360a13). 179. Circa primum duo facit. 179. Regarding the first he does two things: Primo assignat principium materiale ventorum. Et dicit quod, cum dicendum est de spiritibus, idest de ventis, oportet resumere hoc principium, quod iam prius dictum est, scilicet quod sunt duae species exhalationis: una quidem humida, quae vocatur vapor; alia autem sicca, quae, quia non habet nomen commune, a quadam sui parte vocetur fumus; nam fumus proprie dicitur exhalatio sicca lignorum ignitorum. Duae autem hae exhalationes non sic discretae sunt ad invicem, quod humidum sit sine sicco, et siccum sine humido: sed ab eo quod excedit, utraque denominatur. first he assigns the material principle of winds (359b27) and says that, since spirits, i.e., winds, are to be discussed, it is necessary to recall this principle, already enunciated, namely, that there are two kinds of exhalation: one, indeed, is the moist, which is called vapor; the other is the dry, which, having no common name, is called smoke from one of its forms: for smoke is, strictly speaking, the dry exhalation of burning wood. Now these two exhalations are not so independent of each other that the moist is without the dry, and the dry without the moist—rather they are denominated one or the other by that which is predominant in a given case. 180. Secundo ibi: lato autem sole etc., ponit principium efficiens, quod est motus solis. Et dicit quod cum sol suo motu appropinquat ad aliquam partem terrae, sua caliditate elevat humidum: eo autem elongato, vapor elevatus, propter frigiditatem, condensatur in aquam. Et inde est quod in hieme magis pluit quam in aestate, et in nocte quam in die, licet aquae nocturnae lateant propter somnum. Aqua autem pluens dividitur per terram, et bibitur ab ea. In terra autem est multum de calore, ex actione solis et aliorum corporum caelestium; et sol desuper eam calefaciens, non solum attrahit per evaporationem humidum quod supernatat terrae, ut puta aquam maris, fluviorum et stagnorum, sed etiam ipsam terram desiccat, attrahens humorem imbibitum in terra. Quod ergo exhalat ab humido supernatante, dicitur vapor: quod autem exhalat per desiccationem terrae, dicitur fumus; sicut in simili dicitur fumus, quod exhalat a lignis calefactis. 180. second at now when the sun in its circular course approaches (359b34), he mentions the efficient principle, which is the motion of the sun. And he says that when the sun in its course approaches a given region of the earth, its warmth elevates the moist; as the sun recedes, this raised vapor is condensed into water on account of the cold. This is why there is more rain in winter than in summer, and more at night than during the day, although night-rains go unobserved because of sleep. The rain water is divided up in the earth and drunk in by it. In the earth much heat exists, caused by the action of the sun and other heavenly bodies. And the sun overhead, heating the earth, not only draws aloft the moisture resting on the surface of the earth—for example, the water of the sea, rivers and ponds—but also dries out the earth itself and draws up the moisture drunk by the earth. Consequently the exhalation it produces from the moisture resting on the earth is called "vapor," but the exhalation that results from its drying out the earth is called "smoke," just as in a parallel case, the exhalation from heated wood is called "smoke. " 181. Deinde cum dicit: exhalatione autem sicut etc., determinat generationem ventorum. Et dicit quod, cum exhalatio duplex sit, ut dictum est, una vaporosa et alia fumosa, necesse est quod ex motu solis fiat utraque. Ea autem quae plus habet de humido, est principium pluentis aquae, ut supra dictum est (quod dicit propter hoc, quia supra dixerat ei admisceri aliquid de exhalatione sicca): sicca autem exhalatio est principium ventorum. 181. Then when he says, consequently, since there are two kinds of evaporation (360a8), he determines the generation of winds and says that since exhalations are of two kinds, as has been said, one vaporous and one smoky, it is necessary that, from the sun's motion, both should come about. The one with more moisture is the source of rain water, as said above (which he says, because he had previously stated that some dry exhalation is mixed with it); but the dry exhalation is the source of winds. 182. Deinde cum dicit: hoc autem quod isto modo etc., manifestat quod dictum est de generatione ventorum. Et circa hoc tria facit: 182. Then when he says, that things must necessarily take this course (360a13), he manifests what has been said about the generation of winds. About this he does three things: primo hoc manifestat per rationem; first, he manifests it with an argument; secundo ex hoc quod dictum est, excludit falsas opiniones de ventis, ibi: quoniam autem altera etc.; second, from what has been said, he excludes false opinions about winds, at since the two evaporations are specifically distinct (360a17); tertio hoc manifestat per signa, ibi: attestantur autem quae fiunt et cetera. third, he manifests this with signs, at the facts bear out our theory (360a33). Dicit ergo primo quod, cum sit duplex exhalatio, propter duo ex quibus consurgit, scilicet terram et aquam, possibile est, immo necessarium, quod sol et caliditas quae est circa terram, possit causare resolutionem utriusque exhalationis. He says therefore first (360a13) that since exhalations are of two kinds, on account of the two sources from which they are derived, namely, earth and water, it is possible, even necessary, that the sun and the heat which environs the earth can cause the release of both exhalations. 183. Deinde cum dicit: quoniam autem altera etc., excludit falsas opiniones de ventis. Et primo quantum ad hoc, quod dicebant quod eadem natura est venti et pluviae. Quod quidem excludit per hoc, quod diversorum diversi sunt effectus: unde, cum exhalationes differant secundum siccum et humidum, necesse est quod non sit eadem natura venti et natura aquae pluentis, ut quidam posuerunt, dicentes quod idem aer quando movetur, est ventus, quando autem condensatur, fit aqua. Sed, sicut dictum est in libro De generatione, aer habet aliquid vaporis et aliquid fumi. Vapor eius est frigidus et humidus, et bene terminabilis, propter grossitiem: et hoc convenit aeri inquantum est humidus. Sic etiam vapor, qui elevatur ab aqua, est frigidus secundum suam naturam, sicut et aqua non calefacta: sicut autem aqua calefacta remanet frigida secundum naturam, ita et vapor. Sed fumus est calidus et siccus: siccus quidem propter terram, calidus autem propter ignem. Unde manifeste patet quod superior aer, qui est calidus et humidus, habet similitudinem cum utroque. 183. Then when he says, since the two evaporations are specifically distinct (360a17), he dismisses false theories about the winds. First, the opinion of those who said that the natures of wind and of rain are the same. This he excludes by the fact that the effects of diverse things are themselves diverse: hence, since the exhalations differ on the basis of dry and moist, it is necessary that the nature of wind and of rain water be not the same, as some supposed who said that it is the same air which, when moved, is wind, and when condensed, becomes water. But as stated in On Generation, air has something of vapor and of smoke. Its vapor is cold and moist and well-definable by its density; and this belongs to air in so far as it is moist. Thus also vapor, which is borne up from water, is cold by its very nature, as also is unwarmed water: just as warmed water remains cold according to nature, so also vapor. But smoke is hot and dry: because of the earth, it is dry; because of fire, it is hot. Hence it is manifestly plain that the upper air, which is hot and moist, bears a likeness to both. 184. Secundo ibi: etenim inconveniens etc., excludit falsam opinionem quantum ad hoc, quod dicebant quod ventus nihil aliud est quam aer motus. Et dicit quod inconveniens est, si quis existimet quod iste aer qui circumstat unumquemque nostrum, quando movetur est ventus; vel quod unusquisque motus qui accidit in aere, sit ventus; sicut etiam non existimamus fluvium esse aquam qualitercumque fluentem, etiam si multa sit, sed solum quando fluit ex aliquo principio determinato, quod est fons ex terra scaturiens. Sic etiam est de ventis: non enim est ventus, si aer moveatur aliquo modo casu, etiam in magna multitudine, nisi habeat principium, quasi fontem, exhalationem siccam elevatam. Sic igitur non est verum quod aer motus est ventus: tum quia quandoque parvus aer movetur, tum quia non habet principium. 184. second at it is absurd that this air (360a27), he dismisses the false opinion as to its tenet that wind is nothing more than air in motion. And he says that it is unacceptable for anyone to suppose that the air which surrounds each of us is, when in motion, wind; or that every movement occurring in air is wind; just as also we do not suppose any water at all that flows, even if it be a large amount, to be a river, but only when it flows from some determinate source, which is a spring gushing from the earth. The same applies to winds: it is not a wind, if air, even in large amounts, is moved in some chance way, but only when it has as its source, as though its spring, a raised dry exhalation. Consequently, it is not true that air in motion is wind: both because sometimes a small amount of air is in motion, and because it does not have a starting-point. 185. Deinde cum dicit: attestantur autem quae fiunt etc., manifestat quod dictum est de generatione ventorum, per signa. Et dividitur in partes tres, secundum tria signa quae ponit: 185. Then when he says, the facts bear out our theory (360a33), he manifests through signs what has been said about the generation of winds. And it is divided into three parts according to the three signs he gives: secunda pars incipit ibi: adhuc autem post imbres etc.; the second part begins at further, after rain wind generally rises (360b26); tertia ibi: adhuc autem fiendi et cetera. the third part at the cause of the predominance of winds (361a4). Dicit ergo primo quod ea quae fiunt circa ventos et pluvias, attestantur his quae dicta sunt de generatione eorum. Quia enim continue fit exhalatio, licet quandoque magis et quandoque minus, propter hoc nubes, ex quibus causantur pluviae, et venti semper fiunt, secundum quod natura temporis habet: quia quandoque magis fit, quandoque minus, secundum diversam temporis conditionem. Et quia quandoque exhalatio vaporosa plus elevatur, quandoque autem plus de fumosa, secundum diversos effectus solis et stellarum, ideo quandoque fiunt anni magis pluviosi et humidi, quandoque autem magis ventosi et sicci. Quod quidem contingit dupliciter: uno modo secundum unam totam regionem continuam, in qua aliquo tempore multiplicantur pluviae, et aliquo tempore venti; alio modo fit secundum partes. Quandoque enim in una parte unius regionis accidunt multi imbres, in alia vero parte eiusdem regionis accidit multa siccitas: quandoque etiam contingit contrarium, quod tota regio circumstans habet mediocres aquas, vel etiam excedit in siccitate, alia vero abundat multitudine aquarum. Et huius causam assignat, dicens quod causa huius est, quod verisimile est quod eadem passio vel siccitatis vel humiditatis, pertingat frequentius ad multam regionem, ex hoc quod loca quae sunt prope, eandem habent positionem vel situm respectu solis, qui est causa pluviarum et ventorum: nisi forte aliqua habeat aliquid proprium quod immutet dispositionem eius, ut puta montes vel aquas. Sed quamvis ut plurimum hoc accidat, quod tota regio eandem participet passionem, tamen quandoque contingit quod secundum unam partem unius regionis abundet exhalatio sicca, ad generandum ventos, aliquando autem humida, ad generandum pluvias: et quandoque contingit contrarium, ut scilicet ubi olim abundavit pluvia, ibi nunc abundet ventus. Et huiusmodi diversitatis causa est, quia contingit de utraque exhalatione quod transeat in exhalationem alterius regionis habitae, idest consequenter se habentis: ut puta, quandoque sicca exhalatio facit fluxum ventorum in illa regione unde elevatur, sed exhalatio humida a ventis impellitur ad aliquam regionem propinquam terrae ventosae; et aliquando remanet humida, et transfertur sicca. Sicut enim in corpore animalis aliquando superior ventositas, quae ex stomacho exhalat, contrarie disponitur inferiori, quae exhalat ex intestinis; sic et circa loca accidit quod patiuntur quandam contraiacentiam ex permutatione exhalationum; scilicet dum in regione ex qua transfertur exhalatio humida, abundat siccitas, et in illa ad quam transfertur, abundat humiditas. He says therefore first (360a33) that the phenomena attending winds and rains support what has been said about their generation. For because exhalations are continually occurring, now more, now less, clouds producing rain, and winds are forever being generated according to the nature of the season: for according to the varying condition of the season more occurs at one time and less at another. And because more vaporous exhalation is sometimes lifted up and more of the smoky at other times, depending on the diverse effects of the sun and stars, the consequence is that sometimes the years are more rainy and wet, and sometimes more windy and dry. Now this happens in two ways: in one way, with respect to some whole continuous region, where at one time there are many rainstorms and at another many winds; in another way, with respect to various parts. For sometimes in one area of one region many rainstorms occur, and in another area of the same region there is a great drought; at other times the opposite occurs, namely, that the entire surrounding region has middling rain or even drought, while the other has an excessive rainfall. And he assigns the reason, saying that the cause of this is that it is reasonable that the same passion of dryness or dampness should extend often to a whole region, because places that are close to one another have the same position in relation to the sun, which is the cause of rain or of winds—unless one place happens to have a special characteristic which changes its disposition, such as mountains or bodies of water. But although it most frequently happens that an entire region shares the same weather passion, yet it sometimes happens that one locality of a region has an abundance of dry exhalation to generate winds, whereas another abounds in the moist to generate rains; or the opposite happens, i.e., a region that once abounded in rain now abounds in wind. The reason for this diversity is that both types of exhalation can cross over into the exhalation of a had, i.e., following [adjacent] region: for example, the dry exhalation sometimes blows up a wind in the very region from which it was elevated, but the moist exhalation is blown to a region next to the windy one; while sometimes the moist exhalation may remain and the dry migrate. For, just as in the body of an animal the upper flatulence which exhales from the stomach is in a condition contrary to the lower which exhales from the intestines, so, with respect to places, it happens that from the interchanging of exhalations, they undergo a certain counter-state, so that while dryness prevails in the region from which the moist exhalation is transported, moisture abounds in the region to which it is carried. 186. Deinde cum dicit: adhuc autem post imbres etc., ponit secundum signum. Et dicit quod pluries fit ventus post pluvias in locis in quibus pluit; et e converso venti cessant aqua pluente. Et hoc accidit propter hoc quod dictum est de principiis pluviae et ventorum, quia scilicet unum eorum fit ex exhalatione sicca, aliud ex humida. Quia cum pluvia ceciderit et humectaverit terram, iterato a terra exhalat exhalatio sicca, quae est materia ventorum, desiccata ipsa terra tum a caliditate intrinseca, tum a superiori caliditate solis. Et haec est causa quare post pluvias fiunt venti: cum scilicet venti invalescant per separationem talis elevationis a terra. Et cessant propter hoc, quod ex virtute caloris iterato separatur calidus vapor a terra, et elevatur in superiorem locum, et propter frigiditatem ibi condensatur, et fit pluvia: et haec est causa quare post ventos pluviae superveniunt. Nec solum pluviae succedunt ventis, sed etiam destruunt eos: quia cum nubes a vento adunentur in unum locum, frigiditas circumstans condensat eas, et generantur aquae; aqua vero infrigidat et humectat exhalationem siccam, quae erat materia ventorum. Unde manifestum est quod aquae fluentes faciunt cessare ventos, et succedunt, ipsis cessantibus, pluviae, propter praedictas causas. Et hoc accipit ut signum ad ostendendum quod ventus et pluvia fiunt ex causis contrariis. 186. Then when he says, further, after rain wind generally rises (360b26), he gives the second sign, and says that in the places in which it has rained, a wind often arises after the rain; and conversely, the winds stop when it rains. And this occurs because of what has been said about the sources of rain and winds, namely, that the one is from the dry exhalation and the other from the moist. For when the rain has fallen and wet the earth, the dry exhalation, which is the stuff of winds, is once more exhalated from the earth dried out by its own inherent warmth or by that of the sun above. And this is the cause of winds occurring after rains: namely, since winds are increased by the separation of such elevation from the earth. But they cease because the vigor of heat once more separates the warm vapor from the earth, and it is elevated to a higher place where the cold condenses it and forms rain—which is the reason for rains occurring after winds. Rains not only succeed winds but destroy them: for, when clouds are pushed together by a wind into one place, the surrounding cold condenses them and water is generated; the water then cools and dampens the dry exhalation which was the stuff of the winds. Hence it is plain that flowing waters make winds cease, and that, when they cease, the rain succeeds them, for the reasons given. And he takes this as a sign that wind and rain come from contrary causes. 187. Deinde cum dicit: adhuc autem fiendi etc., ponit tertium signum quod venti generentur ab exhalatione sicca. Haec enim est causa quare fiunt venti maxime ab ursa, idest a Septentrione (quod vocatur ab ursa, eo quod duae ursae, maior et minor, circumeunt polum Septentrionalem de propinquo), et iterum a meridie: inter omnes enim ventos magis abundant Boreae, qui sunt a Septentrione, et Austri, qui sunt a meridie. Et huius causa est, quia super ista loca non movetur sol, sed accedit ad ea et recedit ab eis. Ad polum quidem Septentrionalem maxime accedit, cum pervenit ad principium cancri: et tunc incipit ab eo recedere continue magis, quousque perveniat ad principium Capricorni; tunc enim maxime accedit ad polum contrarium, a quo iterum recedens circulariter redit ad principium cancri. Et propter hoc haec duo puncta, scilicet principium cancri et Capricorni, dicuntur tropica, idest conversiva: et quando est in principio cancri, fit versio aestiva, quando autem est in principio Capricorni, versio hiemalis. Ultra autem haec duo signa non accedit ad alterutrum polorum. Sed super orientem et occidentem semper fertur. Et ideo in locis qui lateraliter se habent ad viam solis, multae nubes congregantur: quia appropinquante sole, fit exhalatio humidi propter calorem; recedente autem sole ad locum contrarium, fiunt pluviae et hiemalia frigora. 187. Then when he says, the cause of the predominance of winds (361a4), he gives a third sign that winds are generated from the dry exhalation. For this is the cause why winds blow mostly from the Bear, i.e., from the north (described as from the Bear, because the two "bears," Big and Little, circle closely around the North Pole) and from the south — for it is a fact that most winds are boreal, i.e., from the north, or austral, i.e., from the south. The reason for this is that the sun is not moved over those places but approaches them and then departs. The closest it gets to the north pole is the beginning of Cancer; then it departs farther and farther, until it reaches the beginning of Capricorn, which is its maximum approach to the contrary pole, from which, departing once more, it cyclically returns to the beginning of Cancer. For this reason, these two points, namely, the beginnings of Cancer and of Capricorn, are called tropics, i.e., turning-points: when the sun is in the beginning of Cancer, the summer turn occurs; when it is in the beginning of Capricorn, the winter turn. Beyond these points the sun gets no closer to either pole. But it is always moving over the east and west. And therefore, in the places lateral to the sun's course many clouds gather, because, as the sun approaches, a moist exhalation is formed on account of the heat; after the sun recedes to its opposite place, rains and wintry cold arise. Sic igitur propter hoc quod sol accedit ad tropicos vel recedit, fit aestas et hiems, et elevatur aqua per evaporationem, et iterum pluit. Quia cum in caelo accedit sol ad principium cancri, fit aestas nobis, et elevantur plurimi vapores propter calorem ex vicinitate solis: cum autem accedit ad principium Capricorni, fit nobis frigus et hiems, et multitudo pluviarum, propter elongationem solis a nobis. E converso autem accidit in illa parte terrae sita ad alium polum. Quia igitur in istis locis qui sunt ad meridiem et Septentrionem, plurima aqua descendit, oportet quod ibi etiam plurima fiat exhalatio; sicut ex lignis viridibus et humidis maior exhalat fumus quam ex siccis. Unde, cum exhalatio talis sit principium ventorum, rationabile est quod plures et maximi ventorum sint, qui flant a meridie et vocantur Austri, et qui a Septentrione et vocantur Boreae. Considerandum est tamen quod Aristoteles hic dicit Austrum flare ab alio polo, secundum aliorum opinionem: sed contrarium infra dicet secundum suam opinionem, et aliam causam assignabit de vehementia huius venti. And so, depending on whether the sun is approaching the tropics or departing, summer and winter are produced, and water is raised aloft by evaporation and once more descends. For when the sun in the heavens attains the beginning of Cancer, our summer is produced, and an abundance of vapors are elevated on account of the heat produced by the nearness of the sun; but when it comes to the beginning of Capricorn, cold and winter are produced for us, and many rains come, because of the distance of the sun from us. But the opposite is occurring in that part of the earth situated at the other pole. Since in those regions to the south and north the most water falls, the greatest amount of exhalation must also occur there, just as more smoke is produced from wood green and damp than from dry. Hence, since an exhalation of that type is the source of winds, it is reasonable that more winds and the strongest ones blow from the south and are called "austral," and from the north and are called "boreal." It should be noted that Aristotle here says that the south wind blows from the other pole according to the opinions of others; but later on he will give the opposite as his own opinion and will assign a different cause of the vigor of this wind. Lectio 8 Lecture 8