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Show WIND-S. NoTE XXXIlL explained in Note VII. as well as by their coming into contaCl: with a warmer part of the earth which contributes to make thefe winds greedily abforb moifl:ure in their pa!Tage. On the contrary, the fouth-wcfl: winds, as the atmofphere is fuddenly diminifhed in the polar regions, are drawn as it were into an incipient vacancy, and become therefore expanded in their paffage, and thus generate cold, as explained in Note VII. and are thus induced to part with their moifl:ure, as well as by their contact with a colder part of tire earth's furface. Add to this, that the difference in the found of the north-eail: and fouth wefl: winds may depend on the former being pu(hed forwards by a pre!Turc behind, and the latter falling as it were into a partial or incipient vacancy before; whence the former becomes more condenfed, and the latter more rarefied as it paffes. There is a whiftle, termed a lark-call, which confifl:s of a hollow cylim!er of tin-plate, clofed at each end, about half an inch in diameter and a quarter of an inch high, with oppofite holes about the {ize of a goofe-quill through the centre of each end; if this larkwhiftlc be held between the lips the found of it is manifefl:ly different when the breath is forcibly blown thro•1gh it from within outwards, and when it is fuckcd from without inwards. Perhaps this might be worthy the attention of organ-builders. 5· A Hop is put to this new generation of air, when about a fifteenth of the whole is produced, by its increafing pre!Ture; and a fimilar boundary is fixed to its abforptionor defl:ruCtion by the decreafe of atmofpheric pre!Ture. As water requires more heat to convert it into vapour under a heavy atmofphere than under a light one, fo in letting off the water from muddy fi01-ponds great quantities of air-bubbles are fcen to afcenrl from the bottom, which were previoufly confined there by the preffurc of the water. Similar bubbles of inflammable air are fcen to arife from lakes in many feafons of the year, when the atmofphere fuddenly becomes light. 6. The increafed abforptions and evolutions of air mufl:, like its Gmple cxpanfions, depend much on the prefence or abfence of heat and light, and will hence, in refpetl: to the times and places of its produCtion and defl:ruction, be governed by the approach or retrocdlion of the fun, and on the temperature, in regard to heat, of various latitudes, :and parts of the fame latitude, fo well explained by Mr. Kirwan. 7. Though the immediate caufe of the deflruCtion or reproduction of great maffcs of air at certain times, when the wind changes from north to fouth, or from fouth to north cannot yet be afcertained; yet as there appears greater difficulty in accounting for this change of wind from any other known caufes, we may fl:ill fufpect that there cxifls in the arctic and antarctic circles a BEAR or DRAGON yet unknown to philofophers, which at times fuddenly drinks up, and as fuddenly at other times vomits out one-fifteenth part of the atmofphere: and hope that this or fome future age will learn how to govern anddomefl:icatc amonfler which might be rendereu of fuch important fervice.to mankind. I N S T R U M E N T S. If along with the 11fual regifl:ers of the weather obfervations were made on the winds in many parts of the earth with the three following inflrumcnts which mioht be 0: ' b con ruCted at no great expence, fome ufeful information might be acquired. I. To mark the hour when the wind changes from ~1orth-cafl: to fouth-weft, and the Non: XYXIII. \VI N D s. contrha ry. This mirrht be m d · 9r o annge by m::~ki wcat cr ock to a clock . in fi h ng a communication fro h a tooth of its revolvin~ axi~Jcfhoaurl:lan~1~r, that if the vane flwuld rev:v; ~~~~ane of a edge oTf a ~heel revolving once in twenty~~o~:~\~lock, or put back a fmJ]( b~~ ::u~l: 2. o diicover whether in a . urs. ~rh· . year mor<! !.llr paffed fi trary. IS might be efFected b l . . rom north to fouth h d. . I y P JCII1g a wwdmil! f: ·t f ' or t e con- . w~netcr In a .10llow cylinder about fix in~hcs Ion - a I o copper abollt nine inches emment fituat!On cxaCl.ly north d r I g, open at both ends and fi d {i an wut 1 Tt ' xe on an outh-wcfl: Cllrrents would affect the r ·r r. Ience only a p:lrt of the north-eall d I b 1a1 10 as to tur · 1 . H an countec y an adJpted machm· ery' as the fa i1 w nl dI t' anc If its rcvol ut "I ons were curre~ts of air, and the contrary one . h h ou turn one way with the north count 1 fi · 1 wJt t e fouth cu II g nger cit ler WJY would fllew . h" -h . rrent~, the advance of tl the year. . w lc wmd had prevailed monll Jt the end oJef 3· To chfcovcr the rolling cylinders of . fufpcndcd as to dip or rife vertically as w l~lr, the van.c of a weathercock might be fo '_ e as to have Its horizontal rotation. N RECAPITULATION ORTH·EAST WINDS confifl: of . fl . • fi :llr OWJIW from tl h occa .I Onal.l y p. rod. uced.' ha' s a n apparent d~. rectibo n fro hle nollr t ' .w here it fee ms to be acqUired 111 ItS -JOurney tlte m. crea fim g \'eloCJ.t of hm t e ean owmg to its not ha vm. g analogous to the trade-winds between tl .Y t e e::~rth's furfJce; thefe winJs.are r tl {; r le tropics, and freque tl . non 1S or J OI!f and fix weeks together ,· I . n y contmue in the vernal ·weather. 2. They fomctimes confifl o/ [~\ :~l a ~~gl.l baro~leter, and fair or froft.y over us, driven bJck by a new accum l t. u f -~e. air, which had paffed by us or I u a JOn o air 111 the th T .a (s a y or two, and are atteuded Wl.th r . S N nor . hcfe continue but am. ee ote XXV OUTH-WEST WI NDS confifi of air flowin fro • . abforbed at its arrival to th . h g . m the fouth, and feemmg occafionally [1_ e mole nort ern latnudes It h I d. wen owing to its not havinrr lofl:. . . . as a rea IreClion from the I b 111 Its JOUrney the greater v I . . h d t Je earth's furf3ce from whence .t Th {i . e ocity It a acquired from b 1 came. e e wmds are a I etwcen the tropics and freque tl . • na ogous to the monfoons 1 b ' n y contwue lOr four or fix w k h ow arometer and rainy weather " Th {i . ee s toget er, with a had pa!Ted by us or over us wh: h b-· ey ometrmes confifl: of north-eafl air, which an. · m. the north Th ' IC ecomes retrograde by · d . r · d . a commenc111g efic1ency of · e1e wm s contmue but ad d d . with a Gnking barometer. th . ld b . . ay or two, atten e With feverer froft into an incipient vacancy: eir co emg mcreafed by their expanfion, as they return, benNtO dRowTHn -WdE SdT . WINDS con fIif t ' fi r fl: ' of Cco uth-wefl: winds, which have paffed over us .continu ban d nven back towards the fouth by newly generated northern air. The; 1 ell ut. a ay or two, and are attended with rain or clouds. 2. They confifl of nortl-eau wmds bent do f h h. h ::IC uired a . . wn rom t e lg er parts of the atmofphere, and having there f q . h fgiea.tcr vcloc1ty than the earth's furface are frofty or fair. 3· They confift A0 nol.t -ea t w m.d s formed m· to a vert1·c a 1 1r p1· ral eddy, as on the eafl:ern coalls of North menca, :md bnng feverc frofl. |