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portion of heat. Nottonly do I feel well per suaded of tins fact, bull t.iink t..eeO»»clus.o tvarruujeJ fro in t.e nature and prepert e»'o the food ej-toenuelves. I deem it proper to remark in this place, re it goes liu* in niv maid to corroborate t e ia poc aesis I have assumes and at t-re same tan. is in itself a circumstance nor uhtfte remark ble, t.nat I have uever in tne course oi my l.u met with one of t aese warm bo ese-tner m» mediately succeeding a thuic'er-sto.m. or v< for some time afterward. Ino plain le-iso suppose to be this: trey have been remo.e by tuc combine i operat e i oi t.e c eme its and in their removal, a law is fuifnle.l that i not only iudispensabe in ti e eco omv o m. ture, but in the highest degree be. eficiul u many of her movements. Tne attnorphe « is then no longer cnarge 1 with a bur eiiso.ni portion ot heit : but Irom tne fierce co .cus sions that have take r place it is iende ed re rene, delightful, and heult lful. Tnis bring me more imme lia'elv to t.e po nt w lich I have in view, and w lic’i it is my prere ;t pur pose to explain, namely, the common phenome non of electricity issuhig in profuse up fen did streams from the clouds. T int electricity shoillexst in a considera ble degree, even if it exist at all, in mere v i por, or in t ic higher o • colder regions of tne atmosphere. I behere to be amoit in ruse it ab surdity. Since s lowers of hail are coimno i, we want no furt ler evi.de ice of tne intense cold w.iich prevails in the a gier reg.o is ; and it is utterly repugnant to co nmon sense to imagine that electricity can Ire engendered or preserved umo ig m isses of co lge ;!eJ and congealing water. Whenever the atmosphere becomes loaded with a he ivy portion of vapo \ t ie format on of clouds is the natural co isequeice ; and be ing constantly kept in mot.o i by currents of air, they soon mignify to mi unknown extent of surface and depth. As tre big ier parts must necessarily <o n n micato with those re gions which are atteade I wit i extreme cold, and as their weight must often presst rem very near to the earth, it follows us a tiling of course that their influence becomes botn extensive & powerful. Tne efforts of nk.ure to keep up a general equilibrium in all her movements, are pretty; well understoo 1. Tie e e forts in equ dz ng heat and cold, are familiar to most people.— Tne cool air constantly rus ling through and evi ces into a tight room m ide w irm, sufliciently illustrates tus point; a re-e/e ice, however, to tlie operation of an air-furnace s lows it more conclusively. W ienever, t .e.eio e, a veryj extended bo ly oi* dense vapor is put in mo ho i,j and sweeps over t re eaitn, be ng borne along, l as is frequently the case by stvo ig currents of j cold air, I t.iink it fair to presume that it must attract to itself an immense portion of the 1 heat that is spread over its surface. To my I mind, nothing is mo e evident tnaii thissim-l pie process; for I think tic conclusion follows 1 irresistibly, that t io;c numnro is bo 1 es of neat wnich are slotting o i the surf tee of the ground,; are drawn forcib y into t ie in is.s of cold vapor: j and the inst mt tney come i,i .contact wit a t ie colder and dense! parts, be ng first muc i com pressed, they explo !e, pro lacing tie usual phenomena of viv.d lightning and lo id peals of thunder. Tne d.flereice in tie so ce and duration of explo; o is, 1 ascr.be Jo t ic differ ence in the rn ig.iitu le of tne ,e bo Ires of he it. Beside, in their ascent into t.reeloj Is, it seems quite probable that in nnny instances a junc tion of several may take place. In such cas es, it is reaso iab!e to suppose the concussion becomes pro io t o rally tremeidois. But l do not restrict my view in relatre i to t'l’s point so’cly to those moving bo lies; for t ie belief forces itself very stro igiy upon my m’nd.t mt the influence of an im.nets arable large holy of cold vapor, moving with resistless force through the atm jsp iere, attracts to itself in masses or curre its, all the redundant por tion of he it t nt re n ii ns upo i t ie surf tee o ' the groan!. T iese misses or currents o by w ntever name t ley in iv be ctlle I, are op erate 1 upo l so to ’cibly, 1 1 it t :ev must very soon beco no completely aggregtte 1 holies; that, in their asce it into t ie clo i Is, they are subject to the same operative e foots, and pro duce the same console ices, taat are ascribe I to the bodies of he at w lich have already un dergone review. Indeed, the supposition ap pears to my m ud not u ire iso i thle, that these latter bo lies occis'oi eve i a fiercer coicus sion among tie e!e no its t ian the o hers, so the reason that thev are perhaps larger, and therefore contain within tnenra selves a higher degree of heat. Tab I take to be the natural and true source of those wonderful displays of the electric property.that-em mate in such surprising qunn tiu& frwfla imvily wadgnsed vapor, drives throng winds, which, beyond all nloubt, origin e in h.gii and cold icg.ons. bhomi. e united elfoct of thete Operations, e influence ot wnich must Le inconceivably ~eat, springs tilth extraoidiiiary change m e disposition and cnuracter ol'tire atmosphere .v.iiCii commonly succeeds, und which is at nice so grateful and even so necessary to the existence, health, and comfort of the whole .ninal and vegetable cieation. The air, as etb.e lemarked, is made elastic, pure, and uubr.ous, imparting fresh spirits and vigor to every livn.g tim.g. w.ret.cr animate or mani n.«:e. T e eaitn is ie! eved from the great iK'S . o.dicat that wasspie and over it, and which, .veto .1 of io g continuance, would become i;o o ct er ißsupj o. table. The air by means n.‘ it, would he rendered ui fit tor respiration, md life could i.ot be sustained. In a lew instances 1 have met w ith those >o i cs o; warm air in the forenoon; but fiiis is no common. I lecolleet an instance sev eral ye irs since, in wnicn I had occasion to pass Hudson’s river, opposite the city, early in tne day. Wnen we were near tlie Jersv snore, inano.eu boat, it being about eight o’clock in tne morning, wath a gentle bieeze jfiom the so itn-west, tiie day very sultry, we I pas e I tnrong i two of these bodies of warm air, w lieu were qu.te near each other. They nee.ne l to Ire uncommonly large, and were of ,sucu ail extraordinary degree of warmth, as to attract t.e not.ee of all the passengers. I t link t rey were marked with a higher portion o ' neat t tan any lever recollect to have no ticed. About the hour of five or six in the afternoo i, a fierce tempest came over the citv, and tne clouds discharged a large quantity of hail, attended with a more than ordinary emis sion of tne electric property. Many of the huil-stones were as large as ounce balls. It becomes unnecessary to remark, because the fact is familiar to us all, that after the com mencement of coo! weatiier, wc have seldom any thunder. The reason of this appears suifie e itly obvious. The great portion of oppiessive lieat is withdrawn from this divis ion of the earth, and its place is supplied with air from tiie colder regions. of looming. This phenomenon, I presume, is occasioned soeiy by the agency of tne sun operating on vapo.’. Vapor evidently assumes a very va riable character. Tnat wnich is visible to the eye. and even tangible, goes under the usual denomination of fog. As soon as tiie power o. t .e sun is broug.it to act upon it, it imme diate y becomes ran fie 1, and we see it begin to ascend. After rising to a certain degree of elevation, it forms itself into clouds ; but it of en hangs lor a time on the declivity of ralges. befb;e it attains that region in the at mo.p .e e w lich seems to mark the usual dis tance of the clouds from the earth. Wnile mov ug in the atmosphere, t rey reflect the va ro is snades of light, according to their de gree of density and their position in relation to Ue sun. I Tuee is another kind of vapor of a char acter so extiemely subtile, as to be invisible to t.se eye; tuough, had we sufficient accutcness of visio i to perceive only a small part of the oper t on our wo ulcr, 1 tniiik. would be great ;ly excite!. T iis comes under the general de o ninat on of exhalation or evaporation. It comprises all that immense mass, which, by tne resistless energy of heat, is absorbed from t.e boundless surfaces of water, from the | earth itself, and from every species of vegeta tion. At certain periods, the effect of this is so great, that objects at a moderate distance i are m tde to appear indistinct; although, when superficially examined, the atmosphere pre sents the appearance of much purity and serenity. Fio n the known properties of light and heat, we can readily perceive, that when they a:e bioug it to act o i vapor, the effect becomes I'very striking. Under some circumstances, it | is ma 'e to reflect various hues ; under others, jit becones an extraordinary magnifying pow er. At times, if we cast our eyes across a ;bo ly of water, in order to examine a distant sno e we arc deceive! by an illusion which in so no s tu itlo is is not uncommon, and which >ee;rn to be intimately connected with the present inquiry. Tie water near tile shore, ru t ,e appe trance of being elevated, and pre ■>e it s a real obstacle to a correct view of tlie land. Tne e aie three situations at which tiiis phe lomeno i is sometimes visible when standing on the Battery. One is at the point of Staten Island at the Narrows; another is it t ic K Us, so called, between tbe Jersv shore and the north point of the island; and the third is near Weekavvk, at the distance of boat three miles. , There are also other situa boas qu the East and North river, where it is 1 equally visile. Tl:c cause can he no othe* ! than the infllience oi light and beat on 1. 1 current of evaporation, winch becomes iefie< five, while it serves as a magnifier. It mu. he borne in mind, that ti-esc cilccts are vis. Li. only where high giounds stand m ti e rear, o are contiguous. The! ght tiom ti etc gioum [irobably lias a reacting tendency, assisting n produce the effect in question ; giving to tl-« water the appearance of be- g raised aho.i '.its ordinary level, uccompanfed w.t.i a jeci liarly luminous aspect, it is n y opinion, tna when this happens, cvrq onit.on may ti:e:i be siipjio cd to go on witli greatest ioice ; lor j strd.es my nnnd l! -v* tins law is by no meat., uniform in its action. At t.mes its influence w ould apj ear to be very great; at other time partial; and under some circumstances who! ly suspended. All this I co. ce ve to be owing to tiie state or condition of me atmosphere itself. But I am strongly inclined to believe, that the manner in whic-i evaporate-; goes on, dri fers materially in o-c respect from w hat max perhaps be ti.e general -opimon. It appears to me tiiat the vapor is drawn together in columns or bodies, and ascends in tiiat way ; that it must necessarily be subject to tms mode of operation ; and tiiat t e.-e columns or bo 1 cs in their character and mo cements are very similar to water-spouts, but without the capa bility of producing any visible agitation of the atmosphere, ow ing to their extreme suhtileiy. As t. e ocean presents an extended surface. I think it probable that in some cases these as cending columns are very large; and when tney intervene between a vessel and the land, the effect must be very strong, and consequent ly the more deceiving. I presume this is that kind of illusion which is familiar to seamen when they approach the land, and which, in nautical language, is denominated looming. It sometimes happens during the prevalence of a fog in the bay of* New-Yoik, that objects present tliemsetves to the eye seemingly very large, but which on a near approach are found to be of inconsiderably magnitude. I never beheld a case, however, in which the illusion made the obiect to an; ear so disnro; o.’toned and striking as the o e meat oneu by Mr. Jef ferson.* The difference n:o-t probably aris es from difference of situations. The real cause of ti e deception I take to be this: After the sun has attained considera ble altitude, and by its influence has dissipated the denser part of tne v;q or, the rays of light and heat penetrate through the remaining por tion, producing a stro ig magnifying effiet: and ; when, under these circumstances, an object is placed within a certain distance of an observ er, (but of the real distance required to pio tluce the effect, 1 am finable to speak.) it as sumes a very impo ing aspect, seeming to be much larger than it really is. I think lam correct in asserting, (and to this sentiment 1 attach great we : ght.) that none of these phe nomena were ever noticed either before the sun had risen or after it had set. Hence 1 in for, that their true origin and cause, must be : traced to the influence which light and beat arc generally understood to have on va;or; and which, under some circumstances communi cate to it a high magnifying, and under others | a bright reflecting property. In relation to the singular circumstance ofa mountain in Virginia assuming various and appearently whimsical shapes at certain peri ods, it can, in iny view of the subject, arise from no other conceivable causes but from those at present under view. As before oh. [served, ordinary evaporation is so extremely subtile as to elude our vision ; i evcrtheless, it must at times be ofsuflic'ent density tc conceal a distant object from view. It is known that the atmosphere in high ;i nations is generally cool; and fog is frequently seen extended in *“ Having had occasion to mention the particular situation of Monticello fro her purposes, I will jus; take notice that is clevn-i vi ntf-sals nn opportunity of ! seeing a phenomenon which is ra ! e at lard, ‘hough fre- I quent at sea. The seamen calli" looming. Phi’osophy I is as ye* in the rear of seamen, for so far from having i accou Ved for it, rhe has n a o,if a name. Ls prir.- j cipal rtlect is *o make diva ;t objee;s appear larger, i:i : opposition to ihe general law of vision, by which they are diminished. I knew an instance at York tow ti, | fromwhence die wa-er prosper 1 c istwardlv is withon* termination, wherein a canoe with three men at a great distance, was taken for a ship with its three masts. 1 am little acquainted wi‘h ihe phenomenon as it shows itself at sea; but at Monticcllo it is famliar. There i» a solitary mountain about forty miles off, in the south, whose natural shape, as presented to view tliere, is a regular cone ; but by the effect of looming, it some times subsides almost w holly into rhe horizon ; some times it rises more accu'e and more oleva e J ; some’imes it is hemispherical; and sometimes irs sides are perpen dicular, its top fiat, and as broad as its base. In short, it assumes al times the most whimsical shapes, and all these, perhaps, successively in the same morning. Re-, fraction will not account for this metamorphosis; tha only changes rhe proportions of length and breadth, base and altitude, preserving he general ou'lines. Thm it may make a circle appear eliptical, raise or depress a cone; but by none of its laws, as yet developed, will it make a cixvie appear a square, or a cotie a sphere.” Xfolet on Virginia, •bin honzofifal strata on the top of a riflge, le oming visibly condensed on meeting with the 00l air above. The elfoct on invisible vapor .ve must presume to be the eame; und & times body of it must be supposed to take the same iatG, remaining for a while stationary, (sub ect i exert! dess to very sudden and material iai.ges) coiiccjfling ti e top of the rtidgefrom e sig.it. At ti.e same time, streams of vapor i e sup} o-red to ascend ti otn the foot of the ridge, i.d adhering to its sides in columns or sprro nalogous shaj e, !eu\e the prominent part ex oed to tre view of tire observer. Some ■ mes ti.ese exhalat ons ascend in right lines, md coming in contact with the horizontal =tratu above, it gives to the mountain a quad, angular figure. At other times they are pre. un.ed to follow its sides, and meeting on the op in curved lines, it presents a hemispherical figure. And whatever may be the form as jsumed by the object, whether quadrangular, ! emispherical, conical, sunk in the horizon, or whatever else. 1 foel well assured it is all the e-sect of the same law. In my opinion it can | neither be traced to, nor can it originate from, any other conceivable or assignable cause. It is remarked of ti e mountain in question, ! tiiut it is isolated and solitary, and of a conical >Oi ru. To this circumstance alone must be owing the exhibition of the strange phenomc non. I venture lo assert, that no correspond, ing appearances were ever observed on a moun. tain of any considerable continuity, unless aid. ed by distance and some peculiar circumstan ces, piovided its shape and figure possessed the character of unilbimity. Since the foregoing observations on looming were written, I am altogether satisfied of their correctness, and do not now oiler them as mere matter of speculation. Any persons who wishes to remove fiom his mind every doubt in this respect, can easily do it. There is o: e state of the atmosphere alone in which this phenomenon is visible; and this is not unfre quent in the spring and autumn. In summer or winter it is rarely seen, j Whenever a sudden transition takes place from a warm or sultry, to a refrigerative at* mosphere, this phenomenon is very visible at ti e noi t!i }oa t of Staten Island ; at the Nar rows and at Weehawk, as before stated. The effect is produced solely by action between the two elements, air and water. The air in such cases being dry, and considerably colder than tire water, a powerful evaporation immediate ly ensues; for the plain reason, that an equili brium in the operations of nature must be kept up ; but, as I have already remarked, it cannot be seen until the light acts strongly upon it. Hence it will be found, that it is scarcely per ceptible either before sunrise or after sunset. It will be evident to every observer who is willing to examine for himself, that in a mere ordinary state of the atmosphere, the ridge in New-Jersey, as seen through the Narrows, pre .-cuts an almost even line of considerable eleva t’oa. In a few instances, I have perceived the elfoct of looming to be so strong, that, in the language of Mr. Jefferson, it had almost ‘subsi* ded in the horizon.’ The comb of the ridge only was perceptible, and presented the appear ance of small tufts or points.* This, I think, i goes to confirm the suggestion before made, ! that t.ie vapor ascends in columns. The very jagged appearance of those parts of the ridge, seen under such chcumstauces, I deem con* [elusive on this point. The steam fiom boiling ■ water takes that shape, and still farther illus* | trates the position. It Mr. Jefferson had taken pains to note the state ot the atmosphere, during those periods when t; e mountain of which he speaks pre sented those whimsical appearances, I am well persuaded that he would have found them at no time visible, except durirg the prevalence of such a state of the atmosphere as I have mentioned. Indeed I hesitate not to say, that t ie principles of philosophy will authorize no o*i cr conclusion. And whether on land or on water, the effect is the same, since it must be owing to the same cause. The most skep tical can satisfy themselves in relation to this matter, with very little trouble. In my next nuir <;r, I shall present some facts in relation to the transmission of sound through the air, and offer a theory of thunder showers, and of west and north-west w’inds. * I have several time? since remarked the fact, that he ridge mentioned above was wholly invisible, and hat foo, in an unusually serene state of the atmosphere a hich, however, was highly refrigerative. THE PUBLIC ARE cautioned not to pay any Notts or book ao * counts due to the subscriber, either to WiixiaM .Mcßipe, r>r any oTer person who may present them or collect’on, as »hev are not authorized by me ; and he said William Mcßride having been guilty of a breach jf trust. S. W. BO AG, Charleston. February 17 I7p