N for North, S for South, E for Eaft, and W for

Weft.

Because there is a confiderable Distance between these thirty two Points, fome put a Point between every two, and make fixty four; which are observed in long Voyages.

BUT Mathematicians, finding that Divifion not accurate enough, made as many Points as Degrees on the Horizon. viz. three hundred and fixty, which are expreffed by their Distance from the North and South; but there is not required fo nice a Divifion for the Wind.

YET the thirty two Winds might be better defigned than from the thirty two Points, from which they blow; and this would ferve in all Languages; that is, if they were called the firft, fecond, and third, as they are in order from the one Cardinal to the other.

PROPOSITION VII.

The Antients, both Greeks and Latins, counted few Winds, or rather they gave Names to few; nor are thefe few determinate, one Wind having feveral Names, not taken from any order, which make it bard to understand their feveral Points.

INDEED the Greeks had antiently but the four Cardinal Winds; nor are any more mentioned by Homer and to these they afterwards added four; 1. That was made one where the Sun rifeth at the Winter Solstice, between the South and Eaft, called Eurus; for the Eaft Wind itfelf was called Subfolanus; but Gellius calls the former Vulturnus, and the Eaft Wind Eurus. 2. That Point in which it then fets, called Africus. 3. That where the Sun rifeth in the Summer Solftice, between the Eaft and North; and the Wind from thence was called Aquilo. 4. Where it then fets between North and West, called by the Grecians Corus.

PROPOSITION VIII.

The Defignation of the Winds by the Greeks was very incommodious for Sailors, and others; which Inconvenience they did not much find, not going far from Greece in their Navigations.

FOR in Places of different Latitudes, thofe Divifions they made, were not the fame; yet the Greeks retained them, augmenting them with 'other four intermediate Winds, which they gave Names to, and fo made twelve in all: tho' others among them gave other Names to fome of them.. The Latins added one between every two adjacent Winds; and fo made twenty four. And Seneca fpeaks of their being obferved of old by Varro to be incommodious, and therefore they were fo ordered as to be made equally diftant, without regard to the Place of the Sun's rifing and fetting at different Times of the Year. But what Seneca fays, that there are no more Winds than twelve, is erroneous and ridiculous: For they are infinite.

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PROPOSITION IX.

We have explained the feveral Winds that have their Names from the Points they blow from, and fhewn that the Divifions of the Greeks and Latins are incommodious for Navigation and Geography.

THEREFORE we retain the Divifion of the Moderns into thirty two Winds, equally diftant. And thofe are called opposite and contrary Winds that blow from the Points diametrically oppofite for we confider the Winds as coming from another Place to us; but the Points we conceive as extending from us to another Place.

PROPOSITION X.

The Caufes of the Winds are various; for feeing the Wind is nothing but a continual Impulse of the Air, all thofe things that caufe the one, are Caufes of the other.

1. THE principal and general Caufe is the Sun itself, which, by it's fiery Beams, rarifies and attenuates the Air; efpecially that which is juft under it; and the Air rarified takes up more Room: and hence it is, that the Air thrufts forward the Air next to it; and the Sun going round from Eaft to Weft, the Preffure is made weftward, as appears in moft Places of the Torrid Zone, and every where there on the Sea a continual Eaft Wind blows: and the Air rarified preffes weftward within the Tropics. There is a Preffure indeed all round, but the Air is not admitted to other Points, the Preffure not being fo great as towards the Weft, because the Sun moves that way, but in our Climate, 'tis fo only for the moft

part,

Part, before and after Sun rifing, when there are no other Winds that blow ftronger, and overcome it. And fome Places, or other Points, are more difpofed to receive this Force than others; and therefore when the Air is thrust most to the North, the Wind is faid to blow from the South; and fo of other Winds. And 'tis to be observed, that when this is to any Point between the four Car dinals, then the Wind feems different in different Countries. For tho' the Point, in refpect of the Place the Sun is vertical to, be but one, yet it is different in refpect of other Places. And thus one and the fame Caufe makes a Wind that hath different Names in different Places: if that Cause be af fifted by others the Wind is strong, if hindered but weak. And oft-times another Wind blows that is helped by the general Cause.

2. THE fecond and moft frequent Cause of the Wind, are the Exhalations from Sea and Land that are raised plentifully, and with fome Force; but they do not caufe a Wind 'till they begin to rarify.

3. THE Rarefaction and Attenuation of the Clouds, great or finall, made by the Sun and other Stars, or by the fulphureous Particles and Fire inclosed in a Place.

4. THE melting of Snow and Ice, especially that which lies on high Places: for they are not intirely melted.

5. THE Rifing, and various Situation, of the Moon and Stars.

6. THE Condensation or Rarefaction of the Air and Vapours by Heat or Cold.

7. THE defcending of Clouds that thereby prefs the Air below.

THE Confideration of the Eolipile is of ufe, for understanding these Caufes of the Wind; for the Water inclofed in it, being heated with Fire,

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fends

SECT. VI. fends, out of a fmall Hole of it, a ftrong Steam of Vapours, like a Wind blowing, which continues 'till the Water is all exhaled. The groffer Air that furrounds ferves instead of that small Hole; and fometimes 'tis ftrengthned by other Vapours and little Clouds behind it, and sometimes 'tis condenfed, and fo makes way for the Air to move to that Point.

PROPOSITION XI.

Why the Wind may blow in a Line perpendicular to the Horizon.

THE Reason is, that the Air furrounds the Earth in a fpherical Figure, and the Air is thrust about for the most part in a great Circle of the Earth; and tho' the Air may be also thrust in a tranfverfe Line, yet because the Air doth not prefs fo much, or refifts more at the Sides, therefore the Wind blows in the middle.

WE fhall understand this better if we confider the first Caufe of the Winds. For the Sun thrufts the Air to all the Points of the Place that it is vertical to; but 'tis not received in all these Points, as was faid. If we then confider great Circles to be drawn from that Place, and between thefe, thofe to which the Air is forced, or in which 'tis received, all the Places of the Earth fituated in that Circle, or Semicircle, will feel the Wind coming down perpendicularly; because all great Circles that pass thro' any Place are perpendicular to the Horizon of that Place; for the fame Reafon, if the Wind break out from a Cloud broke, or diffolved, thofe Places that are fituated, beyond thofe Circles will not feel the Wind, tho' the Air move above their Horizon; because 'tis not perpendicular, but oblique to that Horizon.

YET