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Show 524. Earth tend: to freeze, éutfor the Sun. Earth tend: to freeze, éut for the Sun. . r,yer . of this dcfcription_ are ' rown, moun tains is world ior Ollliftslethe way thawedgupNor is this perhaps wonderfull. 1pc hut aloft b the air, when it depofits its mmflure, is returnct to tie fagn kindy when evaporation takes place upon thfc mountainl,t 1;] mom. a" ' of the thaw p roduced.~ Alfo w h en now the is me Ct, d tie Ion confequence . ) . . a g t often pours own ' evaporates, onl thus $33: fidey together with thebuheat that thawed it , As tort-hp} gm 5 1'in the fogs intercept and carry away fomedetlie 1%"; L ILCLHC "tr: ~ it f )u ' or the ubodv ' ‘ * others < a ,_ . .and fnow refluft and ice ‘ ‘ furface, its * ( 1 .. ' heart,- an d what heat it has, now ' offeffes little air ‘ [are chiell'ly meets with) is fuppofed not to conduit well . h How little proportional heat is communicaged by t i'flfliltq/yji; )f the \{p on l otir cl min ' ' feen by the difference foun in e- ‘ _ is to other bodies, . coom‘Uhrthu - and fouth "a ' lls ot a houte, by dtie in s ( tween the neith . (M11011: . .pa Y c r .. ~ ‘ open ' caves an d g rottos, &c. &c. an in ‘ itfelfin air hrmd fl ' covered \Vith A fnow, \ye are told. that it ish ter} the earth is ‘ the frail of the air ‘ to pene trate the. {011. On‘ t ed o l, iermnna t , for ‘11 ' ‘ y b {Dme . flow ly , heat is communicate though how extenfiiely that ‘ . ‘ " ~ of £12th ' r or‘ rum.(or to another, \Vi appear y the from one palthlL ' ‘ ' and com llaries-, which tend to prove h f n remarks additional .wholly. upon t e' u , ' deicnds 1 enerally taken rth's tem eratUie film that wpithout tliis particular heat the earth would reniailn fog ever frozen -I°. Springs and caves. that are free from ininera sfai;1 tried at proper depths, feem to correfpond With the avgragfi-heatfo tt: . s '[cea vera ‘ , they are foun d ,- the earth at certain . ept mg e where climate ‘g ‘ . retainingi sa obe the tem orary' changes 0 fthe fun, and only o elation; or; in other words the {low changing mafiasof the flips: bglow dedufling from or adding to the upper heat, lull, 1p Plow/Mme» as the'fun's heat above exceeds or falls lhort. -- 2*. Idie Vea‘ink is tropics is gradually colder as we havegone lower 1pm}. "n ‘ flill colder in the cold regions, but liquid asfar as t.e oufnthmgt line has gone; Though differing lefs in'the proportion f0. [elm between its furface and lower parts than in the ti‘OPlCQi or". old at bottom ever tolproducc emigeIIILion,_tlieHice being, h riling wouljd i :cicfically liuhter ' mult be expected .to rife,. and. while u\ . ti: melted again quickly by the {ea where it itill remained liqu1 ,V ) , ' ‘ s theory of he :. t,‘ p.. 3).-o.7, and 419-20. Dr.Franklin rticnlarl ' i "‘ ofliiiieelit-erizfl £1311 Cd,-1¥l( be thought thit the mountain ought ‘olbi iiiiiiiriii, irs Contact with the groundfaund a! in biz/(h. it muft be haggliéfidlgpgmnc upon; . d I tel under its e is very .. ; leis, i bafe (\iliitli ' ' ' of tour ‘ ‘ ' ex [enee hriidntchd: lb); parts mummhc bale taken all together, are for very 'vTiousnrggunpscnfi warm below than if .there were no mountain near them. As pediavfe the dillanccx [rated into the earth's bowels downwards more than one-tiir o.t is "or to be fixed by Ulloa for the point of congelation upwards at the‘equaftor, 1‘ & ought to; cxpeéted that we can determine preciiely how lllgll up the ch'eét 0 can a reach. 12.] and . 5 2 55 and thence produce (what is {een ) a pretty even temperat low *; The parts above ure be-v being regulated b y the mixed operation of climate, evaporation, agitation, and conta&.-3°. Though thefe' efleéts depend'upon the fun, yet its light and rays do not penetrate 100 fatho ms into the feet, and not at all into land: confetluently the heat mutt be communicated by conta&.--4°. I conjecture the meiflure of the ground in that our as to heat, is one pl‘l-nClplll. caufe latitudes, by its conducting powers ofthis extenlive diffufion ofwa .by land: for in India during rmth a heat of 112° in the air, ice by be- ing placed in a dry pit, in high ground, and furro unded with ilraw arid blanketting (both had condu étors of heat,) is kept unmel ted' within four or live yards of the furface. And I would all: wheth er» tire down/r produced byfr/y} is not in this refpec‘l of the fame natur e With this dr-ynefs of tail. arifin g from abfeiice of nioiilure; and‘ whether ice is not for various reafo ns a worfe conductor ofheat thban waterP-5 ". ln SlellELTthC inner {urfa ce ofthe ground appears always frozen ; a faft full. intimated hy the want of fprings, and then difcovered by infpeétion in the enurf e of digging for them; whence one may fuppofe that the medium tempe rature of the climate there for a great part of the year, is below the freezing point. 6°. The upper cruil of the furfa ce howev ‘Ililllllli "mum in winter.- 7°. The difference of heat between day and night, winter and fummer, and in different latitudes, all prove the fun's omnipotence; the greater heat and cold (as might be expected where large malfes are in quellion) being always after the mm of the feafon, &c.-8- . Mines appear to keep a fimilar gradation ofheat‘ with that of the tropi .ur mum r Irwin-u: is with them for a few feet thawed in fummer: as with us it iser,only to the fame depth frozen cal feas: theinneriiirfiice here, after the lemon has for fome time turned, being refpe étively warmer or colder than the upper furfzice;.(which fame circ umfiance is difcovered in the- temperature of the {ea at thefe times in uneve n climates, when furrowed up by tlorms.) It may be difficult howe ver on account of miner al and artificial heats, the. forced circulatio of air, and the n warmth of the miners bodies, to acquire a jolt notio n of the temperature of mines, and therefore it would be bell perha ps to examine the wafer ifl'uing in them at different levels, provided it be pure I : and "‘ [This perhaps (allowance being made for-the form of the Wild, for the iillhrtioii above) will help to explain whence it is, that if frefh to leave room, water is let to freeze, the unfrozen refiduum Will always remain at 32°; though the cold is intenfe and equally applies to the water and the ice :-a faé‘t notice by that very accurate d and niodefl experimenter, Mr. Nairne. 13.] . f [The rivers of Siberia therefore have their origin in the fouth, and go on fluid , by means oftlieir united mall'es to ihenorth. In the north probab they ly could no:ave originated, or at letlil hive been perennial. 13.] p I [Many initlultes are daily made, even by philofophicnl perflms, in taking: ‘ lnC temperature ofliquids z-Tthnhertnoineter {hould remain lmml'ftd in {hm at tiicnng . . |