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Show Hag/2f of Clouds ; quiz/J Conjectures. 521 moved, the long hori zontal fitrfilce now cove red by the fliadow, would have no more rays to enlighten it, than before fell fin l the pin. Again: tranfpar o ent air, particularlv when rare at all aficé‘ted by the l‘un' is t'cgaryccln s rays, though colleéle d glafs; abundantly lefs lo than even traufparent wate by ,a burniny r; Tho' both {HE fer the rays to pats through to heatother bodies, and then by communication with grow warm thofe other bodies "‘*.--No w all the moitiure of the earth would probably remain to the fun; for thus (to mcnt ion only on in the polar circles, when the fun is abl'cnt, or even whe n his rays thoot‘feldom and obliquely. In the tropics however, wher rays fall more perpendicula e the {un's rly, and are withdrawn for {hotter periods, and where they traverle a {horter fettion of the atmo l'phere the earth's moitlure appears not decliviz‘y offttrlace appears in only liquid, but warnt.--lt‘a firm/'1 the tropics, that is not oppofed to the fun ; that declivity may inde ed receive few rays in proporti on to its furlhce, and thence its fur-f ace have lefs power in heat incr the air; but as heat is communicated to it by contact with the neig hbourinw {pots of ground, and by other air that is denfe and load ed with dark exhalations and that is heat ed in the Courle ofacontinucd par- {age along an immenfe war m level ofearth ; the general furface of this {mall declivity will appear but little cooler than other more level parts. If a taller eminence howe ver occurs, fueh as a towerinr r mountain ; whole fides are neceflari ly very oblique to the fun, and which can find no other land near it of the fame level to commu- nicate heat to it either by contact or by confiderably warming the air that is to pafs over it, and which has its own air abov e both clear and rare; fuch mountain in its higher parts will. be found in its original freezing cond ition.--If therefore the warm air which Dr. Franklin {uppofes to rgfl' from 1/]: fig at [be eyuazar, and having its humi dity in a [late of tranfparent folu tion, comes near fuch cold mountain; it will gro w turbid and full of vapors or [/Wll/J'; and if thofe vapors are further condenfe and d chilled, they will fall in hail or {now-B ut it may be afked, whether {uch mountain will not gradually allume the temp erature of the rifen air that furrounds it? I anfwer,thatin acourfe of time this may happen; it may already have happened in part: but the chan ge is very flow, a [The fun (other things being alike) has the appearanc e of ailing my! upon bodies that are leafl 05!: to refleé‘t or tranfmit its rays, and its rays ceafe in part to at} as light when they begin to at! as heat. But the common theory is, that heat comifiing in intefline motion, the refleétion of the fun's rays multiplies the number of times oftheir aflion, and increalesbackwards and forwards this motion, and con{equently theirheat. The atmofphere however (the body in quettion) is molt heated by the fun in its lower parts, when it is {omewhat hazy. Ifit were clear, tnthe pmportion of denfity in which it furrounds our earth, rays would be tranfmtttcd lhrough it perhaps for hundreds of miles. E] Xxx 2 for ‘Mfllfllmll ‘H II II. "lull!!!" l: |