WIND. 



owing to the nature and fituation of the land, which, being 

 greatly heated by the fun, rarefies the air exceedingly ; 

 hence the cooler and heavier air from over the fea will keep 

 rufliing in to reftore the equilibrium. 



9. Between the fourth and tenth degrees of north latitude, 

 and between the longitudes of Cape Verd, and the eafternmoft 

 of the Cape Verd ifles, there is a traft of fea fubjefl to 

 perpetual calms, attended with frequent thunder and lijjht- 

 ning, and rains ; whence this part of the fea is called ' The 

 Rains.' Ships in faihng thefe fix degrees are faid to have 

 been fometimes detained whole months. 



The caufe of this feems to be, that the wefterly winds 

 fetting in on this coaft, and meeting the general eailerly 

 wind ni this traft, balance each other, and caufe the calms ; 

 and the vapour carried thither by the hotteft wind, meeting 

 the cooleft, is condenfed, and occafions the very frequent 

 rains. 



The three lad obfervations account for two circumftances 

 which mariners experience in failing from Europe to India, 

 and in the Guinea trade. 



T\iQ JirJ} is the difficulty which fhips, in going to the 

 fouthward, efpecially in the months of July and Auguft, 

 find in paffing between the coaft of Guinea and Brafil, 

 although the breadth of this fea is more than five hundred 

 leagues. This happens, becaufe the S.E. winds at that 

 time of the year commonly extend fome degrees beyond the 

 ordinary limits of four degrees north latitude ; and befides 

 coming fo much foutherly, as to be fometimes fouth, fome- 

 times a point or two to the weft ; it then only remains to ply 

 to windward : and if, on the one fide, they fteer W.S.W. 

 they get a wind more and more eafterly ; but then there 

 is a danger of falling in with the Brafilian coaft, or (hoals ; 

 and if they fteer E.S.E. they fall into the neighbourhood of 

 the coaft of Guinea, from whence they cannot depart without 

 running eafterly as far as the ifland of St. Thomas ; and this 

 is the conftant praftice of all the Guinea fliips. 



Secondly, With regard to all fliips departing from Guinea 

 for Europe, their diieft courfe is northward ; but on this 

 courfe they cannot go, becaufe the coaft bending nearly eail 

 and weft the land is to the northward : therefore, as the winds 

 on tlris coaft are generally between the S. and W.S.W., they 

 are obliged to fteer S.S.E. or S., and with thefe courfes 

 they run off the (hore ; but in fo doing they always find the 

 winds more and more contrary ; fo that when near the fhore 

 they can lie fouth, at a greater diftance they can make 

 no better than S.E., and afterwards E.S.E. ; with which 

 courfes they commonly fetch the ifland of St. Thomas and 

 Cape Lopez, where, finding the winds to the eaftward of 

 the fouth, they fail wefterly with it, till coming to the lati- 

 tude of four degrees fouth, they there find the S.E. winds 

 blowing perpetually. 



On account of thefe general winds, all thofe that ufe the 

 Weft India trade, even thofe bound to Virginia, reckon it 

 their beft courfe to get as foon as they can to the fouthward, 

 that fo they may be certain of a fair and frefti gale to run 

 before it to the weftward ; and for the fame reafon, thofe 

 homeward-bound from America endeavour to gain the lati- 

 tude of thirty degrees, where they firft find the winds begin 

 to be variable ; though the moft ordinary winds in the North 

 Atlantic ocean come from between the fouth and weft. 



10. Between the fouthern latitudes of ten and thirty 

 degrees in the Indian ocean, the general trade-wind about 

 the S.E. by S. is found to blow all the year long in the 

 fame manner as in the like latitude in the Ethiopic ocean ; 

 and during the fix months from May to December, thefe 

 winds reach to within two degrees of the equator ; but 



dunng the other fix months, from November to June, a 

 N.W. wind blows in the traft lying between the third 

 and tentli degrees of fouthern latitude, in the meridian of 

 the north end of Madagafcar ; and between the fecond and 

 twelfth degree of fouth latitude, near the longitude of 

 Sumatra and Java. 



11. In the traft between Sumatra and the African coaft 

 and from three degrees of fouth latitude quite northward 

 to the Afiatic coafts, including the Arabian fea and the 

 gulf of Bengal, the monfoons blow from September to 

 April on the N.E., and from March to Oftober on the 

 S.W. In the former half year the wind is more fteady and 

 gentle, and the weather clearer than in the latter fix months ; 

 and the vvind is more ftrong and fteady in the Arabian fea 

 than in the gulf of Bengal. 



12. Between the ifland of Madagafcar and the coaft of 

 Africa, and thence northward as far as the equator, there 

 is a traft, in which, from April to Oftober, there is a con- 

 ftant frefh S.S.W. wind ; which to the northward changes 

 into the W.S.W. wind, blowing at that time in the Ara- 

 bian fea. 



13. To the eaftward of Sumatra and Malacca on the north 

 of the equator, and along the coafts of Cambodia and 

 China, quite througli the Philippines as far as Japan, 

 the monfoons blow northerly and foutherly ; the northern 

 fetting in about Oftober or November, and the fouthern 

 about May : thefe winds are not quite fo certain as thofe in 

 the Arabian feas. 



14. Between Sumatra and Java to the Aveft, and New 

 Guinea to the eaft, the fame northerly and foutherly winds 

 are obferved ; but the firft half-year monioon inclines to 

 the N.W., and the latter to the S.E. Thefe winds begin 

 a month or fix weeks after thofe in the Chinefe feas fet in, 

 and are quite as variable. 



15. Thefe contrary winds do not Ihift from one point to 

 its oppofite all .at once : in fome places, the time of the 

 change is attended with calms ; in others, by variable winds : 

 and it often happens on the ftiores of Coromandel and 

 China, towards the end of the monfoons, that there are 

 moft violent ftorms, greatly refembling the hurricanes in the 

 Weft Indies ; in which the wind is fo very ftrong, that 

 hardly any thing can refift its force. 



All navigation in the Indian ocean muft ncceflarily be re- 

 gulated by thefe winds ; for if mariners fliould delay their 

 voyages till the contrary monfoon begins, they muft eitlier 

 fail back, or go into harbour, and wait for the return of the 

 trade-wind. 



16. The irregularities of the wind in countries which are 

 farther from the equator than thofe which have been men- 

 tioned above, or nearer to the poles of the earth, are fo 

 great that no particular period has as yet been difcovcred, 

 excepting tliat in particular places certain winds are more 

 hkely to tilow than others. Thus at Liverpool the winds 

 are faid to be wefterly for near two-thirds of the year ; in 

 the fouthern part of Italy, a fouth-eaft wind (called the 

 fchiroccu) blows more frequently than any other wind, &c. 



17. The temperature of a country with refpeft to heat 

 or cold is increafed or diminiftied by winds, according as 

 they come from a hotter or colder part of the world. The 

 north and north-eafterly winds, m this country and all the 

 weftern parts of Europe, are reckoned cold and drying 

 winds. They are cold, becaufe they come from the frozen 

 region of the north pole, or over a great traft of cold land. 

 Their drying quality is derived from their coming principally 

 over land, and from a well-known property of the air'; 

 namely, that warm air can dilTolve, and keep diffolved, s 



9 greater 



