4. That from the Latitude of four Degrees North, to the aforesaid Limits on the South of the Æquator, the Winds are generally and perpetually between the South and East, and most commonly between the South-East and East, observing always this Rule, That on the African side they are more Southerly, on the Brazilian more Easterly, so as to become almost due East, the little deflection they have being still to the Southwards. In this part of the Ocean it has been my fortune to pass a full Year, in an Employment that oblig'd me to regard more than ordinary the Weather, and I found the Winds constantly about the South-East, the most usual Point S E b E; when it was Easterly, it generally blew hard, and was gloomy, dark, and sometimes rainy Weather; if it came to the Southwards it was generally Serene, and a small Gale next to a Calm, but this not very common. But I never saw it to the Westwards of the South, or Northwards of the East.
5. That the Season of the Year has some small effect on these Trade Winds, for that when the Sun is considerable to the Northwards of the Æquator, the South-East Winds, especially in the Straight of this Ocean (if I may so call it) between Brazile and the Coast of Guinea, do vary a Point or two to the Southwards, and the North-East become more Easterly; and on the contrary, when the Sun is towards the Tropick of Capricorn the South-Easterly Winds become more Easterly, and the North-Easterly Winds on this side the Line veere more to the Northwards.
6. That as there is no general Rule that admits not of some Exception, so there is in this Ocean a Tract of Sea wherein the Southerly and South-West Winds are perpetual, viz. all along the Coast of Guinea, for above five hundred Leagues together, from Sierra Leona to the Isle of St. Thomas; for the South-East Trade Wind having pass'd the Line, and approaching the Coast of Guinea within eighty or 100 Leagues, inclines towards the Shore, and becomes S. S. E. and by Degrees, as you come nearer, it veeres about to South, S. S. W. and in with the Land South-West, and sometimes West South-West; which Variation is better express'd in the Mapp hereto annexed, (Vide Plate 2) than it can well be in Words. These are the Winds which are observ'd on this Coast when it blows true, but there are frequent Calms, violent sudden Gusts call'd Tornado's, from all Points of the Compass, and sometimes unwholsome foggy Easterly Winds, call'd Hermitaa by the Natives, which too often infest the Navigation of these parts.
7. That to the Northwards of the Line, between four and ten Degrees of Latitude, and between the Meridians of Cape Virde, and of the Eastermost Islands that bear that Name, there is a Tract of Sea wherein it were improper to say there is any Trade Wind, or yet a Variable; for it seems condemn'd to perpetual Calms, attended with terrible Thunder and Lightning, and Rains so frequent, that our Navigators from thence call this part of the Sea the Rains; the little Winds that are, be only some sudden uncertain Gusts, of very little Continuance and less Extent; so that sometimes each Hour you shall have a different Gale, which dies away into a Calm before another succeed, and in a Fleet of Ships in sight of one another, each shall have the Wind from a several Point of the Compass; with these weak Breezes Ships are oblig'd to make the best of their way to the Southward through the aforesaid six Degrees, wherein 'tis reported some have been detain'd whole Months for want of Wind.
From the three last Observables is shewn the Reason of two notable Occurents in the East-India and Guinea Navigations: The one is, why, notwithstanding the narrowest part of the Sea between Guinea and Brazile be about five hundred Leagues over, yet Ships bound to the Southward, sometimes, especially in the Months of July and August, find a great difficulty to pass it. This happens because of the South-East Winds, at that time of the Year commonly extending some Degrees beyond the ordinary limit of four Degrees North Latitude, and withal they come so much Southerly, as to be sometimes South, sometimes a Point or two to the West; there remains then only to ply to Windward, and if on the one side they stand away W. S. W. they gain the Wind still more and more Easterly; but there is danger of not weathering the Brazilian Shoar, or at least the Shoals upon that Coast. But if upon the other Tack they go away E. S. E. they fall into the Neighbourhood of the Coast of Guinea, from which there is no departing without running Easterly, as far as the Isle of St. Thomas, which is the constant practice of all the Guinea Ships, and which may seem very strange, without the consideration of the sixth Remark, which shews the Reason of it: For being in with the Coast, the Wind blows generally at S. W. and W. S. W. with which Winds they cannot go to the Northward for the Land; and on the other Tack they can lie no nearer the Wind than S. S. E. or South; with these Courses they run off the Shoar, but in so doing they always find the Winds more and more contrary; so that when near the Shoar they could lie South, at a greater distance they can make their way no better than S. E. and afterwards E. S. E. with which Courses they fetch commonly the Isle of St. Thomas and Cape Lopez, where finding the Winds to the Eastward of the South, they keep them favourable, by running away to the Westward in the South Latitude, of three or four Degrees, where the S. E. Winds are perpetual.
For the sake of these general Winds, all those that use the West-Indian Trade, even those bound to Virginia, count it their best Course to get as soon as they can to the Southwards, that so they may be certain of a fair and fresh Gale to run before it to the Westwards; and for the same Reason those homewards bound from America, endeavour to gain the Latitude of thirty Degrees, as soon as possible, where they first find the Winds begin to be variable; tho' the most ordinary Winds in the Northern part of the Atlantick Ocean come from between the South and West.
As to those furious Storms call'd Hurricanes, which are, as it were, peculiar to the Caribbee Isles; and which so dreadfully afflict them in the Month of August, or not much before or after, they do not so properly belong to this place, both by Reason of their small continuance and extent, as likewise because they are not Anniversary, some Years having more than one, and sometimes for several Years together there being none at all. But their Violence is so unconceivable, and their other Phænomena so surprising, that they merit well to be consider'd apart.
What is here said, is to be understood of the Sea Winds at some distance from the Land; for upon and near the Shoars, the Land and Sea Breezes are almost every where sensible; and the great Variety which happens in their Periods, Force and Direction, from the situation of the Mountains, Vallies and Woods, and from the various Texture of the Soil, more or less capable of retaining and reflecting Heat, and of exhaling or condensing Vapours, is such, that it were an endless task, to endeavour to account for them.
II. In the Indian Ocean, the Winds are partly general, as in the Æthiopick Ocean, partly Periodical; that is, half the Year they blow one way, and the other half near upon the opposite Points; and these Points and Times of shifting are different in different parts of this Ocean; the limits of each Tract of Sea, subject to the same Change or Monsoon, are certainly very hard to determine, but the diligence I have used to be rightly inform'd, and the care I have taken therein, has, in a great measure, surmounted that Difficulty; and I am perswaded that the following Particulars may be relied upon.
1. That between the Latitudes of ten Degrees and thirty Degrees South, between Madagascar and Hollandia Nova, the general Trade Wind about the S. E. by E. is found to blow all the Year long, to all Intents and Purposes after the same manner as in the same Latitudes in the Æthiopick Ocean, as it is describ'd in the fourth Remark aforegoing.