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, But the perpetual Commotions it receives from the Gales, and Storms, keep it pure and healthful (2). Neither are those Ventilations beneficial only to the Health, but to the Pleasure alfo of the Inhabitants of the Terraqueous Globe 3 witnefs the Gales which fan us in the Heat of Summer, without which, even in this our temperate Zone, Men are fcarce able to perform the Labours of their Calling,

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that the Morning was Warm, and what Wind ftirred was WestSouth-west, but the Clouds were Thick and Black (as generally they are when Snow enfues) : A little before Noon the Wind vered about to North by West, and fometimes to other Points, the Cloud at the fanie time flying fome North by West, fome SouthWest : About One of the Clock it rained apace, the Clouds flying fometimes North-East, then North, and at laft both Wind and Clouds fettled Northby West: At which time Sleet fell plentifully, and it grew very Cold. From all which I observe, I. That although our Region below was warm, the Region of the Glouds was Cold, as the black fnowy 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 fuperiour Cold had conquered the inferiour 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 Fići, orat. omnes Ventos vel à nive, glacie,

vehementi gelu, fluminibus, &c. spirare necesse judicat. Bartholin. de ufu Nivis; c. I.

(2) It is well observed in my Lord Howard's Voyage to Constantinoplé, 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 Austria be not windy, it is fubjeti 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 ceafes, as foon as the Nile begins to overflow ; although Mr. Böyl attributes it to nitrous Còrpuscles. Determ. Mat. of Effur. Chap. A.

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

Inter cetera itaq; Providentia opera, hoc quoq; aliquis, ut dignum admiratione suspexerit. Non enim ex unâ causà Ventos aut invenit, aut per diverfa difpofuit : fed primum ut aera non finerent pigreftere,fed affiauå rexatione utilem redderent, vitalemq; trafturis. Sen. Nat. Quæst: l. 5. c. 17, 18. All

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e not without Danger of „Health and Life (3), : especially, : the ::::::::: throughout the whole Year do fan the Torrid Zone, and make that Climate an healthful and

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\ f -- ... ! , , , , , , , , , , s 2. , : r : u All thisi: moresident, from the cause asigned a masignan; epidem: Difeafes, particularly the Plague, by my ingenious ‘learned Friend, Dr. Mead; and that is, ăn hot and moiffTem» perament of the Air, which is observed by Hippocrates, Galest, and the general Histories of epidemical Diseases, to attend those Diftempers. Vid. Mead of Poifons, Essay 5. p. 161. But indeed, whether the Caufebe this, or poifonous, malignant Exhalations, as others think, the Winds are however very falutiferoussin fuch Cases, în cooling the Air, and disperfing and driving away the moist or pestiferous Vapours. . . . . . . . . . . . " : (3) 7úly 8. 1707; (&alled for fome time after the Hot-Tuesday) was fo excessively hot and fuffocating, by reason there was no wind stirring, 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, lufy, young Man, was killed by the Heat : And feveral Horses on the Road dropped down and died the fame Day. *** i 3 . . ; * ... ' , ; , , , : , * · * * * In the foregoịng Notes, having taken Notice of fome things relating to Heat, although it be fomewhat out of the way, I hope the Reader will excuse me, if I entertain him with fome Obfervations I made about the Heat of the Air under the Line, com- : pared with the Heat of our Bodies. 7. Patrick, who, as he is ::very accurate in making Barometrical and Thermometrical Instru"ments, had thę Curiofity for the nicer adjusting his Thermometers, to fend-Twö abroad under the Care of Two very fenfible ingenious Men, one to the Northern Lat. of 81 ; the other to the Parts under the Æquinostial : In these two different Climates, * the Places were marked where the Spirits-stood at the fevereft Cold and greatest Heat. And according to these Observations he graduates his Thermometers, with his Standard i compared my Standard Therṁometer, from an the Degrees of Cold, I could make with sat Armoniack, &c. to the greatest Degrees of Heat, * our Thermomèters would reach to. And with the fame Thermometer (of mine) i experimented the greatest Heat of my Body, in July 17o9. * First in än 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 B: After that, in a much : |- - - ; · . - • • • - 3ya

** * *

leasant Habitation, which would otherwifè be carce habitable. , ' ' ' ' To these I might add many other great Conveni- , encies of the Winds in various Enginės, and various Bufineffes. I might particularly infift upon its į: Ufe : : : : : : C : : Regions of the World (†) and Imight particu

: of the general and coafting Trade-Winds, the

Sea, and the Land-Breezes; (4) the óne ferving to carry the Mariner in long Voyages from :::::

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West; the other ferving to waft him to particular i * - 's. : Places;

Day, and indeed nearly as hot as any Day with i ini after I had heated my felf 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 forgotten it) 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 those very Degrees of 284 and 288, the Point of the equatorial Heat falleth. From which Observation it appears, that here is pretty nearly an equal Contemperament of the Warmth of our Bódies, to that of

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Places; the one ferving to carry him into his Harbour, the other : bring:: ... But I should go too far to take notice.òf ticulars (5). Leaving therefore the Winds, I proceed in the next Place to

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C H A P. III. . . . Of the Clouds and Rain.

- T: Clouds and Rain (1)we shall find to be no lefs useful Meteors than the laft 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,

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{} Clouds and Rain are made of Vapours raised from Water, or Moisture only. So that I utterly exclude the Notion of Dry, Terrene Exhalations, or Fumes, talked much of by mest Philosohers; Fumes being really no other than the humid Parts of ies respestively Dry. - .*

These Vapours are demonstratively no other than finalt Bubbles, or Veficulæ detatched from the Waters by the Power of the Solar, or Subterraneous Heat, or both. Of which fee Book 2. chap. 5. Note 2. And being lighter than the Atmosphere, are buoyed up thereby, until they become ofan equal Weight therewith, in forme of its Regions aloft in the Air, or nearer the Earth ; in which those Vapours are formed into Clouds, Rain, Snow, Hail, Light

ning, Dew, Mifts, and other Meteors. - |In this Formation of Meteors the grand Agent is Cold; which commonly, if not always, occupies the superior Regions of the Air ; as is manifest from those Mountains which exalt their lofty Tops into the upper and middle Regions, and are always covered

with Snow and Ice. * . · * * · ·

This Gold, if it approaches near the Earth. presently precipitates the Vapours, either in Dews; or if the Vapours more copioufly ascend, and foon meet the Cold, they are thēn condenfed into Misling, or elfe into Showers of finall Rain, falling in numerous, thick, finall Drops : But if those Vapours are not only copious, but alfo as heavy as our lower Aif it felf, (by means their Bladders are thick and fuller of Water,) in this Cafe they become visible, swim but a little Height above the Earth, and make what we call a Mist or Fog. But if they are a Degree lighter, fo as to mount higher, but not any great Height, as also meet not with Cold enough to condenfe them, nor Wind to diffipate them, they then form an heavy, thick, dark sky, lasting oftentimes for feveral Weeks without either Sun or Rain. And in this Cafe, I have fcarce

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