An entire body of philosophy according to the principles of the famous Renate Des Cartes in three books, (I) the institution ... (II) the history of nature ... (III) a dissertation of the want of sense and knowledge in brute animals ... / written originally in Latin by the learned Anthony Le Grand ; now carefully translated from the last corrections, alterations, and large additions of the author, never yet published ... by Richard Blome.

CHAP. II. Of Winds.

I. Why Winds are more frequent in the Spring and Au∣tumn, than at other Seasons of the Year. WINDS are more frequent in the Spring and Autumn, and do blow with greater violence, than in Summer or Winter.

The Reason why it thus happens in the Spring is, partly because of the melting of Snow, especi∣ally in Mountainous Places; and partly because the pores of the Earth are then opened, and send forth more Steams or Vapours; and partly also because the Air and Vapours are then more rarefied than in Winter. And in Autumn, the reason is to be ascribed to the frequency of Rains that then fall, as well as to the greater quantity of Exhalations; because the Suns moderate heat, which then takes place, doth raise Vapours and Exhalations, but gross ones, and not sufficiently rarefied. Where∣as in the heat of Summer, there are for the most part no winds, for the same reason that Rains are very scarce then; and because the Sun doth too much extenuate the Exhalations, and so pre∣vents them from uniting in that quantity, which is requisit for the Generation of Winds. And in the midst of Winter, winds are less frequent, not only because less quantity of Vapours is at that time raised from the Earth, but also because those which are so raised, are either condensed into Snow, or at least by reason of the cold, are not so rarefied and dispersed as to be able to produce a Wind.

II. Why an East Wind commonly blows in the Morning, and a West wind in the Evening. About the Suns Rising, an East wind is common∣ly perceived, and about Sun Set a Western: which difference they are most sensible of, who sail in the Ocean, at a great distance from Land.

This proceeds from the presence of the Sun, which puts the particles of the Earth in motion, and lifts up Vapours into the Air: For seeing that a great part of the Earth is always illuminated by the Sun, it must of necessity raise many Vapours from thence, which upon its departure fall down again, and betake themselves to the East and Western parts of the World, to succeed in the room of those Vapours which the coldness of the Night hath condensed in those parts: And therefore they

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who live in the Eastern parts, perceive an East-wind; and those in the West, a West-wind. This will appear more clearly by considering the Figure, where ABCD represents the Compass of the * 1.1Earth, S, the Sun opposite to it, who darting his Beams against the Hemisphere ABC, and making Noon at B, and Midnight at D, doth at the same time Set to the People that live at A, and Riseth to them who live at C. For the Vapours about B, which are rarefied by the Heat of the Day, and do by opposite ways tend towards D, viz. by A and by C, to take up the place of those Vapours, which the Cold of the Night hath condensed, do produce a Western-wind at A, where the Sun sets; and an Eastern-wind at C, where the Sun riseth.

III. Whence the difference of Winds doth pro∣ceed. Whence it follows, that the Fermentations that appen between the Tropicks, produce Winds that are either contrary to, or agree with the East-wind, according as that part of the Earth, where they are generated, is differently situated with regard to the Sun: Whence it comes to pass, that the East-wind, which reigns constantly betwixt the Tropicks, is sometimes stronger, and at other times weaker, as Experience sheweth.

I have said before, that this diversity of Winds is most of all perceptible to them that Sail in the vast Ocean; because at Land there be many things that hinder us, that we cannot so well ob∣serve this order of the Winds, viz. the height of Mountains, and the great variety of Cli∣mats.

IV. Why East-winds are dryer, than VVest-winds. East-winds for the most part are dryer; and produce fair and clear weather; whereas those from the West are commonly moist, and bring Vapours.

The Reason hereof must be deduced from the motion of the Air, which is carried about the Earth from East to West: For seeing that the Winds that are generated at C, follow the motion of the Air, they consequently drive before them all the Vapours they meet with, and dissipate them, and so hinder them from being condensed and turn∣ed into Rain. But those which are produc'd in the West A, seeing that they strive against the motion of the Air, and take a different course from it, they stop the motion of the Vapours they meet with, and drive them together into Clouds. And for the same Reason, winds that proceed from the East C, are generally stronger, and blow with greater force, than those that blow from the West A; because those which are forged at C, follow the course of the whole Mass of Air. Or else, because by reason of the longer absence of the Sun, the Vapours are more closely condensed in that part of the Earth which is between C and D, than in that which is betwixt D and A. Now it is certain, that the Condensation of Vapours, con∣tributes to the force and violence of winds; which are by so much the more vehement, the more heavy the parts are whereof they con∣sist.

V. VVhy about the Sea-Coasts, the VVind at Night blows from the Land, and in the Day-time from the Sea. On the Sea-Coast, the winds are found to blow from the Sea in the Day-time, and from the Land in the Night.

This shifting of the Wind depends on the Illu∣mination of the Sun, whereby it differently raiseth up Vapours from the Sea and Earth. For whilst the Sun shines, he commonly raiseth more Vapours from the Sea, than the Earth; because the Earth is dry in many places, and doth not afford such plentiful matter for Vapours, as the Water: And, on the contrary, when the Sun withdraws, more Vapours rise from the Earth, than from the Sea; because the Earth being a compact Body, and abounding with moisture, doth longer retain the Heat imprest upon it, than the Sea. And there∣fore those strong winds, which blow from Mid∣land places upon the Sea, are strongest next to the Shoar; but grow weaker, the further they proceed on the Sea. From whence COLUMBUS, the first Discoverer of the West-Indies, gather'd, that there were other Countries beyond the Atlantick Ocean, and those not far off neither; because he found such strong and violent winds to blow from the Sea towards Europe, which he con∣cluded to be too vehement to proceed from the Sea.

VI. VVhat the Cause is of the winds called Etesiae, and of other Con∣stant winds. There be some Winds that return at certain times, and always observe the same course; as the Etesiae, which every Year blow for 40 Days together, beginning 2 days after the Rising of the Dog-Star. West-winds, which blow from the Vernal Aequinox, to the Autumnal, in the Medi∣terranean Sea: And South-winds, which are pro∣duc'd under the Torrid Zone, and have their daily, monthly, and 6 monthly Returns, or Reci∣procations.

The Sun is the only Cause of all these constant or stationary winds, who, according to his various approaches to, or recesses from the several Parts of the World, effects this great diversity herein. For as to the Etesiae, which are observed after the Summer Solstice, it is probable that they proceed from Vapours, sublimed by the virtue of the Sun from the Earth and Water, that are in the Nor∣thern parts, after that he hath continued a great while about the Tropick of Cancer. For it is cer∣tain, that he continues longer at the Tropicks, than in the Space that is between them. And we are to consider, that in the Months of March, April and May, the greatest part of the Clouds and Snow which were about our Pole, are resolved into vapours and winds; and that these winds, from the beginning of the Spring (at which time they are at the strongest) towards the Summer Solstice do grow weaker, as the Matter of them decreaseth. And that in June, the Earth and VVater is not yet sufficiently heated there, to furnish Matter for a new wind: But when the Sun continues about the Tropick of Cancer, they become more strongly heated, and by this means produce the Ethesiae, when the Noon of that long Day, which con∣tinues there 6 Months, begins a little to de∣cline.

VII. The winds called Or∣nithiae, are near akin to those Etesiae. These Et••siae have a great affinity with the winds called Ornithiae, which blow from South to North, and bring back the Birds from the beyond Sea hotter Countries into Europe, and are there∣fore called Ornithiae, or Bird-blowing-winds. But yet sometimes these winds stop in the midst of their course; and therefore it is observed, that Swal∣lows are very rare in France, when North winds have blown much towards Africa at the beginning of the Spring.

VIII. In the In∣dian Seas, and those of Arabia, the Winds blow con∣stantly. Experience teacheth us, that in the Indian and Arabian Seas, which are so situated with respect to the Continent of Asia, when the Sun heats the same from April to October, the Air which is condensed on the South-side of the Aequator, doth transport it self with so much impetuosity, towards the North-side of it, that it makes the North-east-wind not to be perceived, which blows at the same Latitude in the Atlantick Ocean. And, on the other hand, when the Sun doth heat the Seas which are on the South-side, from Octo∣ber to April, then the Air which becomes con∣densed towards the North by the Cold of the VVinter, that remains there, doth take its course with that violence towards the South, that it doth entirely over-power the South-east-wind. Which is the Reason, why in these Seas there is only per∣ceived a Periodical-wind, which blows one half of the Year on one side of the Aequator, and the other on the other side.

IX. The West-winds blow at a cer∣tain time of the year in the Me∣diterra∣nean. In like manner West-winds usually blow in the Mediterranean-Sea, from the time of the Vernal Aequinox to the Autumnal; because a great quantity of Vapours is, during the Heat of Sum∣mer, drawn up from the Atlantick-Ocean; and some Hours after Sun-Rising, which answer to a set space of Time after Midnight, are driven to wards the East, and continue their activity till Sun-setting. The winds betwixt the Tropicks are certain and stationary; because the Sun there darting direct and perpendicular Rays towards the Earth, doth by this means raise many Vapours, which being put into motion by the Action of the Light, do diffuse themselves and prod••ce a wind. And in like manner it may be said of other winds, which rise at certain times; as of the Southwest-wind by West, which blows from the Eastern-shoar of Africa, towards Mo∣rambique, from the beginning of August to the 15th of September; that they are caused by the Sun, who raiseth plenty of Vapours out of the Indian-Sea, from April to August, which take their course towards Africa, and having got more room, do there dilate themselves.

X. How Arti∣ficial-winds may be made. Winds may be raised by Art, as appears by that Instrument called the Chymists Bellows; which consists of a hollow Copper-Globe, so contrived as that it may be filled with water, and afterwards shut up close; having a Pipe with a very narrow Mouth jetting out from one part of it, which In∣strument thus fill'd with water, is plac'd near a Fire, the Pipe being turn'd towards that Fire which is to be blown up: Whereupon, as soon as this Globe grows hot, the water becomes rarefied, and bursts forth through the narrow Mouth of the Pipe, in the manner of a strong blast or wind, and so serves for a Bellows till all the water be consumed.

In this case the particles of the water being agitated by the fire, dash together, and with strong Endeavours strive to get away from one another; and because they cannot dilate themselves, nor depart from each other, but only so far as some of them get out through the Pipe, all this force wherewith so many of them clash together, being united, doth drive the parts that are next to the Pipe, with great violence into the open Air, and by this means a blast or wind is caused. And forasmuch as by the fires continual Action, other parts of the water are still rarefied, and being whirl'd about, do withdraw from one another, whilst others of them endeavour to get out of the Pipe; by this means the wind ceaseth not, until all the water that is in the Globe be evaporated, or that the fire be removed from it.

XI. Why winds are most vehement in the Winter. Winds do rage most in the Winter, and cause more stormy weather, than at other times; which Sea-men are very well aware of.

The Reason is, because the Sun at that time draws towards the Southern Tropick, and therefor•• occasions a less Resistance against the North-winds. To which may be added, That in the VVinter, the South-west, or South west and by VVest-wind comes down with more force from the Mountain Atlas, or the Southeast-wind from the Mountains of Syria and Arabia. But the VVinds are never more stormy than in March and September, be∣cause the Heaven then is subject to many mutations, and frequent vicissitudes of heat and cold, moisture and drought.

XII. Why the South-wind is unhealth∣ful. The South-wind is, for the most part, unhealth∣ful, and causeth Colds or Stuffings of the Head. Hence it is, that when the South-wind blows, People grow more peevish, and more unfit for their Studies.

The Reason is, because the South-wind being moist, carries many Vapours along with it, which enter into the open pores of the Body, and are carried to the Inward parts of it. Whence pro∣ceed Colds and Stuffings of the Head, and Dulness of the Senses, which when a man perceives, he is apt to be troubled and peevish; and consequently is less disposed for his Studies, or other Affairs, that require a clear and serene Mind.

XIII. Why the North-wind com∣monly brings fair weather, and the South-wind, Rain. Northern-winds do clear the Air, and cause Fair∣weather.

Because by their impetuous blasts they drive away and disperse the Clouds that are already formed, and by their Coldness hinder the Genera∣tion of New ones: Whereas on the contrary, South winds must needs produce a quite different Temperature in the Air, which is abundantly confirm'd by Experience in the Isle of France, Burgundy and Campagne, whither the South-wind always brings great Rains; for being opposed to the course of those Vapours, that are raised towards the North, and which blow towards the South, it stops them, and by its heat, doth in a short time change them into showers.

XIV. Some winds blow only in some particular Regions. There are some winds that blow in some parti∣cular Countries only; as that North-wind which blows on the West-side of the Alps. Such also is the North-east-wind in Apulia, and in other places.

The Reason of these VVinds must be deduced from the situation of the several Places, the Nar∣rowness of the Valleys, and the Caverns of the Mountains. For it is evident, that a wind must blow with greater violence between the Streights of Mountains, by the same Reason that the water of a River runs more swiftly where its Channel is streightest, because the Fore-parts of the water are prest forwards by those that are behind. And therefore it is, that a VVind that breaks from a streight place into an open Country, doth rage with an extraordinary violence.

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XV. Why the North∣wind is cold, and the South, hot. The North-wind is generally Cold, because it passeth through a Region cover'd with Snow, whence it brings many cold Vapours along with it. But the South-wind is Hot, because it comes to us from those parts that are nearer to the Torrid Zone, whence it brings along many hot Exhala∣tions, which the Sun hath call'd forth, which makes it to feel hot to us. This Mr. BOYLE made an Experiment of in a Weather-Glass, in which there was a hanging Cylinder, or long Glass-Pipe fill'd with Water, and after having blown into it with a pair of Bellows, the water did not fall down, as it happens when the Cold is increased; but on the contrary, the Glass-Pipe began to grow hot, and received some degree of warmth upon blowing in of the wind: But when the outside of the Bellows was surrounded with a mixture of Snow and Salt, a colder wind came forth from it, and made the hanging water to de∣scend. By which Experiment it sufficiently ap∣pears, that all winds bring some Steams and Exha∣lations along with them, that impart a different Temperature to the Air, which they fan with their Blasts.

XVI. The Winds that blow in Tempe∣rate Zones are Irregu∣lar. The winds that bear sway in these Temperate Zones, are generally irregular; that is, are tied to no certain Rules or Laws.

The Cause of this Inconstancy is to be fetched from the different situation of the Zones; for seeing that the Temperate Zones are placed be∣twixt the Torrid and the Polar frigid Zone, they sometimes receive the most intense heat from the former; and at other times, most extream cold from the latter. Whereas the Cold and Hot Zones, for the contrary Reason, are accustomed to more Regular winds, which at certain set-times use to be very violent. Thus because Southern-winds with us, do most of all depend on the different force of Exhalations, therefore also they are free, and tied up to no Laws.

XVII. Winds blow regu∣larly only, on the Main Sea. But after all, it may be said, that winds are scarcely Regular to exactness, save only on the Main-Sea, where the Fermentations that com∣monly happen in the Earth, cannot produce any Alteration; and that on the contrary, on the Land and in Seas, that are not very far from it, the winds must needs appear with all the Irregularities imaginable; not only with respect to the different parts of the Horizon, whence they blow, but also with respect to the force wherewith they exert their activity.

XVIII. The most violent Winds are dry, and the most gentle are the moistest. The most violent winds are such as are dry; and the most gentle and soft, are those that are moistest.

The Reason is, because the most violent winds are able to carry away with them the watry par∣ticles that are in the pores of Bodies, that are exposed to their action; whereas on the contrary, the softest and gentlest winds must needs be the moistest; not only because the particles of Air, and the Vapours whereof they are composed, are not of force enough to carry away the particles of the water, which are either in the pores, or on the surface of Bodies which they meet with; but also because the Vapours which are in the wind, being only endued with a small degree of Agita∣tion, do stop at those Bodies, and make them moist.

XIX. Why the Wind h••th so great force against the Sails of a Ship. A wind blowing against a Plate of Iron, or a wooden Board, exerts but little force upon it; whereas when it is driven against the Sails of a Ship, it hath so great a force as to drive forwards the greatest Ships so swiftly, as that they can run near 80 Leagues in 24 Hours.

The Reason of this difference is to be ascribed to the difference of the pores in these several Bo∣dies; for those that are in Sails are formed by the weaving of Threds, through which, when the wind passeth, it doth as it were divide it self at the several Threds of the Sail, that separate the pores from each other, and exerts its force against them: Like a Torrent of water, which exerts a greater violence against a Dam, that hath slits or intervals between them, than against a wooden Board, or a stone Wall, which affords no passage to any part of the water.

XX. VVhy the VVind is felt colder than the Air, where∣as indeed it is not colder than it. Winds seem to be colder, than the still and calm Air, tho' they be little or nothing colder than it, as may be seen in a Weather-Glass, in which the water doth not mount higher when the wind blows, which yet ought to be, in case the Air that is shut up in the Glass, were made colder by the outward wind.

The Reason is, because the still Air doth only reach the outside of our Skin, which being colder than the Flesh which is hid under it, is therefore less sensible of the Cold that comes against it: Whereas the wind being more agitated, is driven deeper into our Bodies, and piercing the Flesh, is conveyed into the Inward parts, which being much hotter than the Skin, are more sensible of the coldness of the wind that reacheth them. For the same Reason that a hot Hand is made sensible of more cold when it touches a piece of Ice, than a Hand which is only luke-warm.

Notes

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  Figure 24.