FOOTNOTES:
[a] Ventus est aer fluens, is Seneca’s Definition, Na. Qu. l. 5. And as Wind is a Current of the Air, so that which excites or alters its Currents may be justly said to be the Cause of the Winds. An Æquipoise of the Atmosphere produceth a Calm; but if that Æquipoise be more or less taken off, a Stream of Air, or Wind, is thereby accordingly produced either stronger or weaker, swifter or slower. And divers things there are that may make such Alterations in the Æquipoise or Balance of the Atmosphere, viz. Eruptions of Vapours from Sea or Land; Rarefactions and Condensations in one Place more than another; the falling of Rain, pressure of the Clouds, &c. Pliny, l. 2. c. 45. tells us of a certain Cavern in Dalmatia, called Senta, in quem, saith he, dejecto levi pondere, quamvis tranquillo die, turbini similis emicat procella. But as to Caves it is observed, that they often emit Winds more or less. Dr. Connor, taking notice of this matter, specifies these, In regno Neapolitano ex immani Cumanæ Sibyllæ antro tenuem ventum effluentem percepi. The like he observed at the Caves at Baiæ, and in some of the Mines of Germany, and in the large Salt-Mines of Cracow in Poland. Ubi, saith he, opifices, & ipse fodinæ dominus Andreas Morstin, Nob. Polonus, mihi asseruerunt, quòd tanta aliquando Ventorum tempestas ex ambagiosis hujus fodinæ recessibus surgere solebat, quod laborantes fossores humi prosternebat, nec non portas & domiciliæ (quæ sibi in hâc fodinâ artifices exstruunt) penitùs evertebat. Bern. Connor. Dissert. Med. Phys. p. 33. Artic. 3.
And as great Caves, so great Lakes sometimes send forth Winds. So Gassendus saith the Lacus Legnius doth, E quo dum exoritur fumus, nubes haud dubiê creanda est, quæ sit brevi in tempestatem sævissimam exoneranda. Gassend. Vit. Peiresk. l. 5. P. 417.
But the most universal and constant Alterations of the Balance of the Atmosphere are from Heat and Cold. This is manifest in the General Trade-Winds, blowing all the Year between the Tropicks from East to West: if the Cause thereof be (as some ingenious Men imagine) the Sun’s daily Progress round that part of the Globe, and by his Heat rarefying one part of the Air, whilst the cooler and heavier Air behind presseth after. So the Sea and Land Breezes in [Note (d).] And so in our Climate, the Northerly and Southerly Winds (commonly esteemed the Causes of cold and warm Weather), are really the Effects of the Cold or Warmth of the Atmosphere: Of which I have had so many Confirmations, that I have no doubt of it. As for Instance, it is not uncommon to see a warm Southerly Wind, suddenly changed to the North, by the fall of Snow or Hail; to see the Wind in a frosty, cold Morning North, and when the Sun hath well warmed the Earth and Air, you may observe it to wheel about towards the Southerly Quarters; and again to turn Northerly or Easterly in the cold Evening. It is from hence also, that in Thunder-Showers the Wind and Clouds are oftentimes contrary to one another, (especially if Hail falls) the sultry Weather below directing the Wind one way; and the Cold above the Clouds another way. I took Notice upon March the 10ᵗʰ 1710/1, (and divers such like Instances I have had before and since) that the Morning was warm, and what Wind stirred was West-South-West, but the Clouds were thick and black (as generally they are when Snow ensues): A little before Noon the Wind veered about to North by West, and sometimes to other Points, the Clouds at the same time flying some North by West, some South-West: About one of the Clock it rained apace, the Clouds flying sometimes North-East, then North, and at last both Wind and Clouds settled North by West; At which time Sleet fell plentifully, and it grew very cold. From all which I observe, 1. That although our Region below was warm, the Region of the Clouds was cold, as the black, snowy Clouds shewed. 2. That the struggle between the warmth of ours, and the cold of the cloudy Region, stopped the airy Currents of both Regions. 3. That the falling of the Snow through our warmer Air melted into Rain at first; but that it became Sleet after the superiour Cold had conquered the inferiour Warmth. 4. That, as that Cold prevailed by Degrees, so by Degrees it wheeled about both the Winds and Clouds from the Northwards towards the South.
Hippocrates, l. 2. De Vict. Orat. Omnes Ventos vel à nive, glacie, vehementi gelu, fluminibus, &c. spirare necesse judicat, Bartholin. de usu Nivis, c. 1.
[] It is well observed in my Lord Howards Voyage to Constantinople, that at Vienna they have frequent Winds, which if they cease long in Summer, the Plague often ensues: So that it is now grown into a Proverb, that if Austria be not windy, it is subject to Contagion. Bohun of Wind, p. 213.
From some such Commotions of the Air I imagine it is, that at Grand Cairo the Plague immediately ceases, as soon as the Nile begins to overflow; although Mr. Boyl attributes it to nitrous Corpuscles. Determ. Nat. of Effluv. Chap. 4.
Nulla enim propemodum regio est, quæ non habeat aliquem flatum ex se nascentem, & circa se cadentem.
Inter cætera itaq; Providentiæ opera, hoc quoq; aliquis, ut dignum admiratione suspexerit. Non enim ex unâ causâ Ventos aut invenit, aut per diversa disposuit: sed primum ut aera non sinerent pigrescere, sed assiduâ vexatione utilem redderens, vitaiemq; tracturis. Sen. Nat. Quæst. l. 5. c. 17, 18.
All this is more evident, from the Cause assigned to malignant epidemical Diseases, particularly the Plague, by my ingenious, learned Friend, Dr. Mead; and that is, an hot and moist Temperament of the Air, which is observed by Hippocrates, Galen, and the general Histories of Epidemical Diseases, to attend those Distempers. Vid. Mead of Poisons, Essay 5. p. 161. But indeed, whether the Cause be this, or poisonous, malignant Exhalations or Animalcules, as others think, the Winds are however very salutiferous in such Cases, in cooling the Air, and dispersing and driving away the moist or pestiferous Vapours.
[c] July 8. 1707, (called for some time after the Hot Tuesday,) was so excessively hot and suffocating, by reason there was no Wind stirring, that divers Persons died, or were in great Danger of Death, in their Harvest-Work. Particularly one who had formerly been my Servant, a healthy, lusty, young Man, was killed by the Heat: And several Horses on the Road dropped down and died the same Day.
In the foregoing Notes, having Notice of some Things relating to Heat, although it be somewhat out of the way, I hope the Reader will excuse me, if I entertain him with some Observations 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 Thermometrical Instruments, had the Curiosity for the nicer adjusting his Thermometers, to send two abroad under the Care of two very sensible, ingenious Men; one to the Northern Lat. of 81; the other to the Parts under the Æquinoctial: In these two different Climates, the Places were marked where the Spirits stood at the severest Cold and greatest Heat. And according to these Observations 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 same Thermometer (of mine) I experimented the greatest Heat of my Body, in July 1709. First in an hot Day without Exercise, by patting 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 my self with strong Exercise too, as much as I could well bear, I again tried the same Experiment, but could not get the Spirits above 288 Tenths; which I thought an inconsiderable Difference, for so seemingly a very different Heat of my Body. But from some Experiments I have made (altho’ I have unfortunately forgotten them) in very cold Weather, I imagine the Heat of an healthy Body to be always much the same in the warmest Parts thereof, both in Summer and Winter. Now between those very Degrees of 284 and 288, the Point of the equatorial Heat falleth. From which Observation it appears, that there is pretty nearly an equal Contemperament of the Warmth of our Bodies, to that of the hottest Part of the Atmosphere inhabited by us.
If the Proportion of the Degrees of Heat be desired 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 Isaac Newton, in Phil. Transact. Nᵒ. 270.
[d] In hoc Providentia ac Dispositor ille Mundi Deus, aera ventis exercendum dedit,——non ut nos classes partem freti occupaturas compleremus milite armato, &c. Dedit ille ventos ad custodiendam cœli terrarumq; temperiem, ad evocandas supprimendásq; aquas, ad alendos satorum atq; arborum fructus; quos ad maturitatem cum aliis causis adducit ipsa jactatio, attrahens cibum in summa, & ne torpeat, promovens. Dedit ventos ad ulteriora noscenda: fuisset enim imperitum animal, & fine magnâ experientiâ rerum Homo, si circumscriberetur natalis soli fine. Dedit ventos ut commoda cujusq; regionis fierent communia; non ut legiones equitemq; gestarent, nec ut perniciosa gentibus arma transveherent. Seneca, ibid.
[e] Sea-Breezes commonly rise in the Morning about nine a Clock.——They first 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 Comparison. In half an Hours time after it has reached the Shore, it fans pretty briskly, and so encreaseth gradually till twelve a Clock; then it is commonly strongest, and lasts so till two or three, a very brisk Gale.——After three it begins to die away again, and gradually withdraws its force till all is spent; and about five a Clock——it is lulled asleep, and comes no more till next morning.
And as the Sea Breezes do blow in the Day, and rest in the Night; so on the contrary [The Land-Breezes] blow in the Night, and rest in the Day, alternately succeeding each other.——They spring up between six and twelve at Night, and last till six, eight, or ten in the Morning. Dampier’s Disc. of Winds, ch. 4.
[f] One Thing more I believe some of my Friends will expect from me is, that I shew the Result of comparing my own Observations of the Winds, with others they know I have from Ireland, Switzerland, Italy, France, New-England, and some of our Parts of England. But the Observations being some of them but of one Year, and most of the rest of but a few Years, I have not been able to determine any great Matters. The chief of what I have observed is, that the Winds in all these Places seldom agree, but when they most certainly do so, it is commonly when the Winds are strong, and of long continuance in the same Quarter: And more I think in the Northerly and Easterly, 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 distant. Vid. Phil. Trans. Nᵒ. 297, and 321. But to give a good and tolerable Account of this or any other of the Weather, it is necessary to have good Histories thereof from all Parts; which, as yet we have but few of, and they imperfect, for want of longer and sufficient Observations.
CHAP. III.
Of the Clouds and Rain.
The Clouds and Rain[a] we shall find to be no less useful Meteors than the last mentioned; as is manifest in the refreshing pleasant Shades which the Clouds afford, and the fertile Dews and Showers which they pour down on the Trees and Plants, which would languish and die with perpetual Drought, but are hereby made Verdant and Flourishing, Gay and Ornamental; so that (as the Psalmist saith, Psal. lxv. 12, 13.) The little Hills rejoice on every side, and the Valleys shout for Joy, they also sing.
And, if to these Uses, we should add the Origine of Fountains and Rivers, to Vapours and the Rains, as some of the most eminent modern Philosophers[] have done, we should have another Instance of the great Use and Benefit of that Meteor.
And now, if we reflect upon this necessary Appendage of the Terraqueous Globe, the Atmosphere; and consider the absolute Necessity thereof to many Uses of our Globe, and its great Convenience to the whole: And in a Word, that it answereth all the Ends and Purposes that we can suppose there can be for such an Appendage: Who can but own this to be the Contrivance, the Work of the great Creator? Who would ever say or imagine such a Body, so different from the Globe it serves, could be made by Chance, or be adapted so exactly to all those forementioned grand Ends, by any other Efficient than by the Power and Wisdom of the infinite God! Who would not rather, from so noble a Work, readily acknowledge the Workman[c] and as easily conclude the Atmosphere to be made by God, as an Instrument wrought by its Power, any Pneumatick Engine, to be contrived and made by Man!