SECT. VI. few Winds, for the fame Caufe for which there are Rains but feldom then; viz. that the Sun does too much attenuate the Exhalations, and fuffers them not to go fo much together as is neceffary to produce Wind. Which Caufe is not indeed general, nor always true; nor is it generally true, that there are no Winds in the hot Summer, but only that it often happens fo. In a fevere Winter there are few Winds; becaufe few Vapours are then exhaled, and thofe that are raised are either condenfed to Snow, or elfe are not fo rarified or diffipated thro' the Cold, as to cause a Wind.

PROPOSITION XIX.

In what Altitude, or in what Region, of the Air, do the Winds begin to blow?

SOME think they are not above the lower Region of the Air; because the Tops of high Mountains, as Olympus, are found to have no Wind on them. I doubt the Truth thereof, for the Smoke from the Top of Mount Etna is feen to be toffed here and there; and therefore I think there may be fuch a Commotion of the Air in the higheft Region alfo.

PROPOSITION XX.

How far may one and the fame Wind blow?

THERE is a great Difference in this Matter; for the Winds blowing from East to West, under the Torrid Zone, feem to go round the Earth; and thofe alfo that biow thither from the South or North use to accompany the Seamen a great way for many Days. The fame feems alfo true of collateral Winds; but here lies the Difference, that the

fame

fame Winds differ in different Places, as we said under Prop. 10. at the end of the Explication of the firft Cause.

CHAP. XXI.

Of the Kinds of Winds, and of Tempests.

N the preceding Chapter we gave the Divifion of the Winds, their Differences, or rather different Names, which they have from the several Points they seem to blow from. This Divifion was therefore accidental, and refpecting a certain Place on the Earth, which thefe Points referred to. We shall in this Chapter give other Divifions and Properties of the Winds belonging to certain Places of the Earth, or certain Times of the Year; tho' we wish we had more and exacter Obfervations of them. But we fhall produce fome that we have gathered with much Pains from the Journals of Sailors.

PROPOSITION I.

Some Winds are conftant, others inconftant.

THE conftant are fuch as blow at least one Hour, or two, from the fame Point.

THE inconftant are fuch as blow one while from one Point, and another while from another, in a fmall Time.

THE Cause of their fhort continuance in one Point, and of their changing on a fudden, seems

to

to be first their proceeding from a general Cause, or a Caufe that is more or lefs durable.

THUS the Winds that proceed from the Motion of the Air with the Sun are conftant; and those likewise that proceed from the melting of the Snow efpecially in high Places. 2. There being no fuch Vapours in that Quarter the Wind blows from as are fit to make Wind. 3. If the Air about the Cloud, from which the Wind comes, be thicker, and hinder it's Paffage; but if the Air is not thick or close together, and but a few Vapours, here and there, in the feveral Quarters; or laftly, if the general Caufes do not operate there, then the Wind is found to be changeable, and for the most part gentle.

PROPOSITION II.

There is a General and Particular Wind.

THAT is called by Sailors a General Wind which blows in feveral Places at one Time, thro' a large Tract of the Earth, almost all the Year round.

AND this Wind is hindered, 1. In Places of the Sea near Land; for here they drive against the Vapours that come from other Points; and therefore 'tis in the middle of the Sea that this General Wind is obferved. 2. There may alfo blow another Wind in the middle of the Sea, when there is a Cloud, or fome other Cause in another Point, ftrong enough to produce Wind. From thefe two Caufes it is that the Geral Winds are not fo conftant as they might be otherwife.

THESE General Winds are found only between the Tropics round the Earth, except in fome Places where they are feven Degrees beyond the

Tropics;

Tropics; and they are ever from the East, or from collateral Points, as South-East and NorthEast, and that the whole Year round; yet not always with the fame Degree of Force in all those Places, but they are hindered in fome Places more, in others lefs. They are most constant in the Pacific Sea; viz. that Part of it which lies between the Tropics; fo that the Ships which come from the Aquapulco, a Port in New Spain in America, to the Phillippine Islands, that is, from East to West, often fail three Months without ever changing or fhifting their Sails; having a constant Eaft or NorthEaft Wind: nor did ever any Ship yet perish in that vaft Voyage of one thoufand fix hundred and fifty Miles. And therefore the Sailors think they may fleep there fecurely nor is there any need of taking care of the Ship, when that General Wind carries them ftrait to their defired Port, the Philippine Ifles; near to which indeed there are some other Winds that come against the General Wind. And thus 'tis alfo in failing from the Cape of Good-Hope to Brafil in America; in the middle of which Voyage lies the Isle of St Helena, to which they commonly go as they return from India to Europe, and lies about three hundred and fifty Miles from the faid Cape: which is run oft-times in fixteen Days, and fometimes in twelve, as the General Winds are more or lefs ftrong; and the Seamen are as fecure when they come to the fame Parallel of Latitude with St Helena (for the Cape is beyond the South Tropic); their chiefeft care is to obferve that they do not pass by the Island, as 'tis very fmall, for if they pafs it but the eighth part of a Mile, they cannot return to it for the eafterly Wind. Thus they are forced to go to Brafil for fresh Water, or the other Ifland called Afcenfion with great lofs of Time.

IF it be asked how they fail when they come the contrary way, i. e. from the Philippines to New Spain, or from Brafil to the Cape of Good-Hope going to India; in thefe Voyages the Reader muft obferve a threefold Artifice; for either they fail the Sea beyond the Tropics, (and thus do not go to St Helena while they go from Europe to India), or when they fail within the Tropics they do not go directly from Weft to East but obliquely, from the North, or a Point collateral to it, to the South, and fome Point collateral to it; or laftly, they chuse those Times for failing in which they know the General Wind is often diverted: but this laft feldom happens, and therefore the other two are more frequent; of which we fhall fay more in the Chapter of Navigation.

THERE are then two Seas under the Torrid Zone in which the General Wind, from the East and collateral Points, prevails thro' the whole Year viz, that between South Africa and Brafil, and that between America and the Oriental Ifles, of which the Philippines are a Part. And the third Part of this Sea in the Torrid Zone, viz. between South Africa and the Oriental Ifles, is not without the General Wind; tho' 'tis often interrupted because of the many Islands there; and more in fome Places than others. This Wind blows most between Mozambique, in Africa, and India, in the Months of January, February, March, April; and in the rest of the Months other Winds blow, of which in the following Propofition: This general Wind is more hindered in the Seas among the Indian Ifles. The Eaft Winds begin to blow hard in the Month of May at the Ifle of Banda, with fome Rain; and at Malacca in September; and in other Places otherwife, as will be fhewn in the following Propofition.

YET this General Wind does not happen alike near the Tropic in all Places, but extends itself diffe