OCR Text |
Show R A RA they contain, their Air is contracted into alefs Space, and confequently their watry Shell or Cafe rendred thicker, fo as to become heavier than the Air, &c. Others only allow the Cold a Part in the Adtion, and bring in the Winds as Sharers with it: Inc Jeed it is clear, that a Wind blowing againft a Cloud, will driveits Ve/icule upon one another: by which Means feveral of them coalefcing as before, will be enabled to defcend, and the Effect will ftill be more confiderable, if two oppofite Winds blow towards the fame Place. Add to this, tl Clouds already form'd, happening to be aggregated byfrefh Acceflions of Vapourcontinually alcending, maythence be enabled to deicend. : The Wind may collect the Vapours in fuch ce, as firft to form very thick Clouds, hen to {queezethofe C| together, till the watery Particles make Drops too big to hangin the Air. But the grand Caufe, according to Monfieur Robault, is till behinc I; he conceives it to be the Heat of the Air, which after continuing for fome time the Earth, is at length carried up on high by a Wind, andthere thawing the frozen Villi or Flocks of the half- frozen / them into Drops, which coalefcing € ; and have their Diffolution perfected in their Progrefs through the lower and warmer Stages of the Atmo- form a heavy, thick, dark Sky, which lafts fometimes feveral Weeks. a account for many of the Pheher, e.g. Why acold, js Uitarea wet Sun er, and a warm, a dry one; becaufe the Principle of Pr Ipitationis had in the one Cafe, and wanting in the other, Why we have ordinarily moft Rai the Equinoxes; becaule ‘the V p more ‘plentifully ne ordisnary in the arth 2EcOME Ganttics d a aufe as the ‘San r from us in Au! 5ae Cold increafi Vapours that ha di] red above, during the Summer H y dil{pateh’ d dopwn, Why af 1 Re till it ha the acor condenfedanc to lay the Means the reft of t c left open, and pervious to the Sun, &e. Monf. Le Clerc obferves not produce great Quantity of Vapours, ‘Thus in Ho ‘eft Winds r they come from the Oce Vapours5 Eajft Wi lov 7 come iny, Deawie andothers, afcribe this Defcent of the Clouds rather to Alteration of the Atmofphere than ofth cule, and fupp fe it to proceed fron a Diminution of the S ag orelaftick Force oft This Elafticity chiefly, or wholly, on the dry, halations being weakened, the At finks under its: Burthe upon the RA its Sublimation, which may with fome Propriety, like Pails-full than i ops . And it is very pro- be call’d either Salt or Nitre, and both thefe Becaufe atthat are ufeful in the Bufinefs of Veg tion. e bable that this is the Time the Sun draws up abundance of Vapours, Rain is operative in diffolving the Salés that and rarefies them extremely, fo that they are are in the Earth, and alfo cools 2and bathesthe pours down for feveral Weeks together, more elevated Las high as cipitated at on le, p and then are pres and heavy Cortex or Skin ion all Vegetables, and by a fort of Relaxatio » caufes the Sap to pafs up to hang any longerin the Air; and befides, more freely, and Concurrence of there may fometimes be ch will be ready neighbouring Vapour ‘art in the Air, which is to crowd into tl motft ratefied by the Heat of the Sun meeting raifed in that with the Vapours, which are and Rain. sreat Cl Place, and produce v If any ask how the Drops af falling Water cometo be rouncd, asin Rain? It is anfwered, That this does not haypeen by any Difpofition peculiar to the Water; but beccaufe the Drops are equally prefled |by the Air one aeoteorced into a round Figure: the Particles, as well as the he ( being equal every Way; 3 or ive othe but ot In Rain, there Species; the one lution of the is a Ter7 i are two diftiné which ferves for ta DiffoEarth, and the othe r of the iter, which it meets with in that Means the Tree to growand fhoot thebetter. Thefe foggy, humid Vap oursarifing out of the Greound, of which Rain is formed, would iney ftagnate i whole Face of limated by the Air, anc 1 1 Affiftance of the Sun upper but bei re. rare they are made of fecond f As to the Quantity of Rain that falls, its Proportionin { al Places at the fame Time, andin the far lace at feveral Times, we have Store of Obfervations, Journals, @&c. i e Me moirs of the French Academy, the fions, &c. an Idea of which pon meafuring, then, the Raifalling arly, it s ae at a Medium, is found as in the following Table ; and its Proportion in feveral Places. y erved by Mr. Zownley Derbam but not fo rainy as th North does not yield fu 42 + Inches pours, as the kinder Climate of the 4 Ocean: South Winds bri that they confifting Heat of the Sun, in of Vapours raifed by the < t Qu r, and fo being clevated above to lie upon our Clou towards the Ez But notw ceptions in thofe C: Bey of Caui 1700 1701 1702 1703 1704 19 Inches 03 Cent. 18 69 20 38 2 99 15 Si 1705 16 produced ‘after this fo great h to condenfe or diffi pate them, they abundance, t h Clouds above them, then very large Drops, 1 this fill, fultry Weat which are over o Motion, and in the the Air with V. Jbuas, with the Depthat 1708 Now, by how and foonet any fuch Cloucqd ie e the Drops th a great er Store of \ apours ndenfed ther n thenceit is, that in un have fudden Showers of & Drops. It ought alfo to be remembred, that in thofe Countrie ich lie between the Trop ICKSs where they have the Sun Vertical, the pot 21 Inches 38 Cent. 78 93 ve anotl oa eee fe Seasons fo one anot of the RAIN Of tue Jeveral Pifa |——- --—— Inc a weave Foras they fame Point, iz. the Ce of the the farther they £ fe ill, the more ill they make, and the more Coalitions more Matter there will be under the Surface, the Surface only increafing as the S¢ s, but the Solidity as the Cubes; and the more Matter under the fame Surface, the lefs Frition or Refiftancetherewiil be to the fame Me Thus if the Cold, the Wind, to act early enough to precipitate a Vi erethey avearrived at any confiderable He the Coalitions beiing fewin fo fhort a Deft the Drops will be proportionably fmall; and thus is yo m’d what we call De apours prove more copious, and 1er, we have a Mi/t or F & JA little igher f and they produce a fmall Rain, If they ne 1 Cold or Wind At PARrs, At UpmiInsTer. HalfYeat ema rs} oo ‘Now the Title Veficule, by any or all of thef@ Means, being once upon tt he Defcent, will perfift ther notwith{tanding the InMomen Depth a Depth at Zurich | Depthat Depth at fingPifa can Inch. ° 2 Depch at U; mit ifter Inch. I | Inch. i8 é | I oO | ait 7 | 50 15 cD2 24 62 62 |