Refpiration, as well as Health and Pleasure, a ftagnating, confined, pent-up Air is. And if the whole Mafs of Air and Vapours was always at Reft, and without Motion, inftead of refreshing and animating, it would, fuffocate, and poifon all the World: But

tempeftatem fævissimam exoneranda. Gaffend. Vit. Peiresk. 1. 5.

P. 417.

But the most univerfal and conftant Alterations of the Balance of the Atmosphere, are from Heat and Cold. This is manifeft in the general Trade-Winds, blowing all the Year between the Tropicks from Eaft to Weft: If the Cause thereof be (as fome ingenious Men imagine) the Sun's daily Progrefs round that Part of the Globe, and by his Heat rarefying one Part of the Air, whilft the cooler and heavier Air behind preffeth after. So the Sea and Land Breezes in Note d. And fo in our Climate the Northerly and Southerly Winds (Commonly esteemed the Caufes of cold and warm Weather,) are really the Effects of the Cold or Warmth of the Atmosphere: Of which I have had fo many Confirmations, that I have no Doubt of it. As for Inftance, it is not uncommon to fee a warm Southerly Wind, fuddenly changed to the North, by the Fall of Snow or Hail; to fee the Wind in a frofty, cold Morning, North, and when the Sun hath well warmed the Earth and Air, you may obferve it to wheel about towards the Southerly Quarters and again to turn Northerly or Easterly in the cold Evening. It is from hence alfo, that in Thunder-Showers the Wind and Clouds are oftentimes contrary to one another, (especially if Hail falls) the fultry Weather be low directing the Wind one way, and the Cold above the Clouds another Way. I took Notice upon March the 10th, 1710-11, (and divers fuch like Inftances I have had before and fince) that the Morning was warm, and what Wind ftirred was Weft-South-West, but the Clouds were thick and black (as generally they are when Snow enfues :) A little before Noon the Wind veered about to North by Weft, and fometimes to other Points, the Clouds at the fame time flying fome North by Weft, but fome South-Weft: About One of the Clock it rained apace, the Clouds flying fometimes NorthEaft, then North, and at laft both Wind and Clouds fettled North by Weft; at which Time Sleet fell plentifully, and it grew very cold. From all which I obferve, 1, That although our Region below was warm, the Region of the Clouds was cold, as the black, fnowy Clouds fhewed. 2. That

the

But the perpetual Commotions it receives from the Gales and Storms, keep it pure and healthful (b).

Neither are thofe Ventilations beneficial only to the Health, but to the Pleasure alfo of the Inhabitants of the Terraqueous Globe; witnefs the Gales which fan us in the Heat of Summer; without which, even in this our temperate Zone, Men are scarce able to perform the Labours of their Calling,

or

ons.

the Struggle between the Warmth of ours, and the Cold of the cloudy Region, stopped the airy Currents of both Regi3. That the falling of the Snow thro' our warmer Air melted into Rain at firft; but that it became Sleet after the fuperior Cold had conquered the inferior Warmth. 4. That, as that Cold prevailed by Degrees, fo by Degrees it wheeled about both the Winds and Clouds from the Northwards towards the South.

Hippocrates, 1. 2. De Vict. Orat. Omnes Ventos vel à nive, glacie, vehementi gelu, fluminibus, &c. fpirare necesse judicat. Bartholin. de ufu Nivis, c. I.

(b) It is well obferved in my Lord Howard's Voyage to Conftantinople, That at Vienna they have frequent Winds, which if they ceafe long in Summer, the Plague often enfues: So that it is now grown into a Proverb, That if Auftria be not windy, it is subject to Contagion. Bohun of Wind, p. 213.

From fome fuch Commotions of the Air I imagine it is, that at Grand Cairo the Plague immediately ceases, as foon as the Nile begins to overflow; although Mr. Boyle attributes it to nitrous Corpufcles. Determ. Nat. of Effluv. Chap. 4.

Nulla enim propemodum regio eft, quæ non habeat aliquem flatum ex fe nafcentem, & circa fe cadentem.

Inter cætera itaque Providentiæ opera, hoc quoque aliquis, ut dignum admiratione jufpexerit. Non enim ex una causâ Ventos aut invenit, aut per diverfa difpofuit: fed primum ut aera non finerent pigrefcere, fed affiduâ vexatione utilem redderent, vitalemque tra&turis. Sen. Nat. Quæft. 1. 5. c. 17, 18.

All this is more evident, from the Caufe affign'd to malig. nant epidemical Difeafes, particularly the Plague, by my ingenious, learned Friend, Dr. Mead; and that is, an hot and moift Temperament of the Air, which is obferved by Hippocrates, Galen, and the general Hiftories of Epidemical Difeafes, to attend thofe Diftempers. Vide Mead of Poyfons, Efay 5. P. 161. But indeed, whether the Caufe be this, or poifonous, malignant Exhalations or Animalcules, as others think,

the

or not without Danger of Health and Life (c). But especially, witnefs the perpetual Gales which throughout the whole Year do fan the Torrid Zone, and make that Climate an healthful and pleasant Habi

the Winds are however very falutiferous in fuch Cafes, in cooling the Air, and difperfing and driving away the moist or peftiferous Vapours.

(c) July 8. 1707. (called for fome time after the Hot Tuef day,) was fo exceffively hot and fuffocating, by reason there was no Wind ftirring, that divers Perfons died, or were in great Danger of Death, in their Harveft-Work. Particularly one who had formerly been my Servant, a healthy, lufty, young Man, was killed by the Heat; and feveral Horfes on the Road dropped down and died the fame Day..

In the foregoing Notes having taken Notice of fome Things relating to Heat, altho' it be fomewhat out of the way, I hope the Reader will excufe me, if I entertain him with fome Obfervations I made about the Heat of the Air under the Line, compared with the Heat of our Bodies. J. Patrick, who, as he is very accurate in making Barometrical and Ther mometrical Inftruments, had the Curiofity, for the nicer adjufting his Thermometers, to fend two abroad (under the Care of two very fenfible ingenious Men) one to the Northern Lat. of 81; the other to the Parts under the Equinoctial: In these two different Climates, the Places were marked where the Spirits food at the fevereft Cold and greatest Heat. And according to these Obfervations he graduates his Thermometers. With his Standard I compared my Standard Thermometer, from all the Degrees of Cold, I could make with Sal Armoniack, &c. to the greatest Degrees of Heat our Thermometers would reach to. And with the fame Thermometer (of mine) I experimented the greateft Heat of my Body, in July, 1709. Firft in an hot Day without Exercife, by putting the Ball of my Thermometer under my Armpits, and other hottest Parts of my Body. By which means the Spirits were raised 284 Tenths of an Inch above the Ball. After that in a much hotter Day, and indeed nearly as hot as any Day with us, and after I had heated myself with ftrong Exercife too, as much as I could well bear, I again tried the fame Experiment, but could not get the Spirits above 288 Tenths; which I thought an inconfiderable Difference for fo feemingly a very different Heat of my Body. But from fome Experiments I have made (altho' I have unfortunately forgot

C

ten

Habitation, which would otherwise be scarce habi

table.

To these I might add many other great Conveniencies of the Winds in various Engines, and various Bufineffes. I might particularly infift upon its great Ufe to transport Men to the fartheft diftant Regions of the World; (d) and I might particularly speak of the general and coafting Trade-Winds, the Sea, and the Land-Breezes; (e) the one ferving to carry the Mariner in long Voyages from Eaft to Weft; the other ferving to waft him to particular Places;

ten them) in very cold Weather, I imagine the Heat of an healthy Body to be always much the fame in the warmest Parts thereof, both in Summer and Winter. Now between thofe very Degrees of 284, and 288, the Point of the Equatorial Heat falleth. From which Obfervation it appears, that there is pretty nearly an equal Contemperament of the Warmth of our Bodies, to that of the hotteft Part of the Atmosphere inhabited by us.

If the Proportion of the Degrees of Heat be defired from the Freezing Point, to the Winter, Spring, and Summer Air, the Heat of Man's Body, of heated Water, melted Metals, and so to actual Fire; an Account may be met with of it, by my most ingenious Friend, the great Sir Ifaac Newton, in Phil. Tranfa&t. No 270.

(d) In hoc Providentia ac Difpofitor ille Mundi Deus, aera ventis exercendum dedit,- -non ut nos classes partem freti occupaturas compleremus milite armato, &c. Dedit ille ventos ad cuftodiendam cali terrarumque temperiem, ad evocandas fupprimen→ dafque aquas, ad alendos fatorum atque arbcrum fructus ; quos ad maturitatem cum aliis caufis adducit ipfa jactatio, attrahens cibum in fumma, & ne torpeat, promovens. Dedit ventos ad ulteriora nofcenda: fuiffet enim imperitum animal, & fine magnâ experientia rerum Homo, fi circumfcriberetur natalis foli fine. Dedit ventos ut commoda cujufque regionis fierent communia; non ut legiones equitemque geftarent, nec ut perniciofa gentibus arma tranf weberent. Seneca, ibid.

(e) Sea-Breezes commonly rife in the Morning about Nine a Clock.- -They firft approach the Shore gently, as if they were afraid to come near it. It comes in a fine, small, black Curle upon the Water, whereas all the Sea between it and the Shore (not yet reached by it) is as smooth and even as Glass in

Compa

Places; the one ferving to carry him into his Harbour, the other to bring him out. But I fhould go too far to take Notice of all Particulars (ƒ). Leaving therefore the Winds, I proceed, in the next Place, to the Clouds and Rain.

Comparison. In balf an Hour's Time after it has reached the Shore, it fans pretty briskly, and fo increafeth gradually till Twelve a Clock; then it is commonly the ftrangeft, and lafts fo till Two or Three, a very brifk Gale. -After Three it begins to die away again, and gradually withdraws its Force till all is spent ; and about Five a Clockit is lulled afleep, and comes no more till next Morning.

And as the Sea Breezes do blow in the Day, and reft in the Night; fo on the contrary [the Land-Breezes] blow in the Night, and reft in the Day, alternately fucceeding each other. They Spring up between Six and Twelve at Night, and laft till Six, Eight, or Ten in the Morning. Dampier's Difc. of Winds, chap. 4.

(f) One Thing more I believe fome of my Friends will expect from me is, That I fhew the Refult of comparing my own Observations of the Winds, with others they know I have from Ireland, Switzerland, Italy, France, New-England, and fome of our Parts of England. But the Observations being, fome of them, but of one Year, and moft of the rest of but a few Years, I have not been able to determine any great Matters. The Chief of what I have Obferved is, That the Winds in all thefe Places feldom agree; but when they most certainly do so, it is commonly when the Winds are strong, and of long Continuance in the fame Quarter: And more, I think, in the Northerly and Eafterly, than other Points. Also, a strong Wind in one Place, is oftentimes a weak one in another Place, or moderate, according as Places have been nearer or farther diftant. Vide Philofoph. Tranfa&t. No 297, and 321. But to give a good and tolerable Account of this, or any other of the Weather, it is neceffary to have good Hiftories thereof from all Parts; which, as yet we have but few of, and they imperfect, for want of longer and fufficient Observations,