WIN 



WINCKHEIM, in Geography, a town of the duchy of 

 Wurzburg ; 4 miles N.N.W. of Lauringen. 



WINCRANTUM, in Natural Hi/lory, a name given 

 by the people of the Eaft Indies to a foffile fubftance refem- 

 bling, in fome degree, the plated lead ores of Europe, but 

 containing very little of that metal ; it is properly a fpecies 

 of blende, or mock-lead, of a talcky appearance ; it is 

 confiderably hard, and is ufually found in other ftones. It 

 is given in medicine in the Indies as a provocative to venery, 

 being firll calcined and beat to powder. 



WIND, Ven'tus, a fenfible agitation of the air, by 

 which a large quantity of it flows in a current or ftream out 

 of one place, or region, into another. See Meteoro- 

 logy. 



The winds are divided into perennial, Jlated, and variable. 



They are alfo divided into general and particular. 



Winds, Perennial or Conjlant, are fuch as always blow 

 the fame way. 



Of thefe we have a very notable one between the two tro- 

 pics, blowing conftantly from eaft to weft ; called the gene- 

 ral trade-tvind. 



Winds, Stated ot Periodical, are fuch as conftantly return 

 sX certain times. Such are the fea and land breezes, blow- 

 ing from fea to land in the evening ; and from land to fea m 

 the morning. 



Such alfo are iheJhiftingoT particular trade-winds, which, 

 for certain months of the year, blow one way, and the reft 

 -of the year the contrary way. See TRAiiK-lVinds. 



Winds, Variable or Erratic, are fuch as blow now this, 

 row that way ; and are now up, now hufhed, without any 

 •rule or regularity, either as to time or place. 



Such are all the winds obferved in the inland parts of 

 England, &c. though feveral of thefe claim their certain 

 times of the day. Thus, the <wej} wind is moft frequent 

 about noon ; ihefouth wind in the night ; the north in the 

 morning, &c. 



Wind, General, is fuch a one, as at the fame time blows 

 the fame way, over a very large traft of ground, almoft all 

 the year. Such only is the general trade-wind. 



But even this has its interruption : for, i. At land it is 

 fcarcely fenfible at all, as being broken by the interpofition 

 of mountains, valleys, &c. 2. At fea, near the ftiore, it is 

 difturbed by vapours, exhalations, and particular winds, 

 blowing from landward ; fo that it is chiefly confidered as 

 general, only at mid-fea : where, 3. It is liable to be dif- 

 turbed, by clouds driving from other quarters. 



Winds, Particular, include all others, excepting the 

 general trade-winds ; which fee. 



Thofe peculiar to one little canton, or part, are called 

 topical or provincial winds. Such is the north wind, on the 

 weftern fide of the Alps, which does not blow above one or 

 two leagues lengthwife, and much lefs in breadth : fuch alfo 

 is the pontias in France, &c. 



Winds, Phyfical Caufe of. Some philofophers, as Des 

 Cartes, RohauTt, &c. account for the general wind, from 

 the diurnal rotation of the earth, and from this general wind 

 derive all the particular ones. The atmofphere, fay they, 

 invefting the earth, and moving round it ; that part will 

 perform its circuit fooneft which has the fmalleft circle to 

 defcribe : the air, therefore, near the equator, will require 

 a fomewhat longer time to perform its courfe in, from weft 

 to eaft, than that nearer the poles. 



Thus, as the earth turns eaftward, the particles of the 

 aiir near the equinoftial, being exceedingly light, are left be- 

 hind ; fo that, in refpeft of the earth's furftce, they move 

 eaftwards, and become a conftant eafterly wind. 



This opinion feems confirmed by this, th.at thefe winds 



W I N 



are found only between the tropics, in thofe parallels of la- 

 titude where the diurnal motion is fwifteft. But the conftant 

 calms in the Atlantic fea near the equator, the wefterly 

 winds near the coaft of Guinea, and the periodical wefterly 

 monfoons under the equator in the Indian feas, declare the 

 infufficiency of this hypothefis. 



Befides, the air, being kept clofe to the earth by the prin- 

 ciple of gravity, would, in time, acquire the fame degree 

 of velocity that the earth's furface moves with, as well in 

 refpeft of the diurnal rotation, as of the annual, about the 

 fun, which is about thirty times fwifter. See Trade- 

 mndi. 



Dr. Halley, therefore, fubftitutes another caufe, capable 

 of producing a like conftant effeft, not liable to the fame 

 objeftions, but agreeable to the known properties of the 

 elements of water and air, and the laws of the motion of 

 fluid bodies. Such a one is the aftion of the fun's beams 

 upon the air and water, as he pafles every day over the ocean, 

 confidered together with the quahty of the foil, and the 

 fituation of the adjoining continents. 



According to the laws of ftatics, the air, which is lefs 

 rarefied or expanded by heat, and confequently is more pon- 

 derous, muft have a motion towards thofe parts of it which 

 are more rarefied, and lefs ponderous, to bring it to an equi- 

 librium ; alfo, the prefence of the fun continually ftiifting 

 to the weftward, that part towards which the air tends, by 

 reafon of the rarefaftion made by his greateft meridian heat, 

 is, with him, carried weftward ; and, confequently, the ten- 

 dency of the whole body of the lower air is that way. 



Thus a general eafterly wind is formed, which being im- 

 prefled upon the air of a vaft ocean, the parts impel one the 

 other, and fo keep moving till the next return of the fun, by 

 which fo much of the motion as was loft is again reftored ; 

 and thus the eafterly wind is made perpetual. 



From the fame principle it follows, that this eafterly wind 

 ftiould, on the north fide of the equator, be to the north- 

 ward of the eaft, and in fouth latitudes to the fouthward of 

 it ; for, near the line, the air is much more rarefied than at a 

 greater diftance from it ; becaufe the fun is twice in a year 

 vertical there, and at no time dittant above 23^ degrees ; at 

 which diftance, the heat, being as the fine of the angle of 

 incidence, is but little fhort of that of the perpendicular ray ; 

 whereas under the tropics, though the fun ftay longer verti- 

 cal, yet he is a long time 47 degrees off', which is a kind of 

 winter, in which the air fo cools, as that the fummer heat 

 cannot warm it to the fame degree with that under 

 the equator. Wherefore, the air towards the north and 

 fouth being lefs rarefied than that in the middle, it fol- i 

 lows, that from both fides it ought to tend towards the 

 equator. 



This motion, compounded with the former eafterly wind, 

 accounts for all the phenomena of the general trade-winds, 

 which, if the whole furface of the globe was fea, would 

 undoubtedly blow quite round the world, as they are found 

 to do in the Atlantic and the Ethiopic oceans. But fee- 

 ing that fo great continents do interpofe, and break the con- 

 tinuity of the ocean, regard muft be had to the nature cf 

 the foil, and the pofition of the high mountains, which are 

 the two principal caufes of the variations of the wind from 

 the former general rule ; for if a country lying near the fun 

 prove to be flat, fandy, and low land, fuch as the deferts of 

 Lybia are ufually reported to be, the heat occafioned by the 

 reflexions of the fun's beams, and the retention of it in the 

 fand, is incredible to thofe who have not felt it ; by which 

 the air being exceedingly rarefied, it is neceflary that the 

 cooler and more denfe air fhould run thitherwards, to reftore 

 the equilibrium. This is fuppofed to be the caufe, why, 



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