appearing above the waters in the form "deftractive ocean had taken poffef. of islands. "fion of thefe fpoils, or at least that "there had been islands above the fur"face" "The fea, he fays, being con"tinually agitated, muft neceffarily "wear away its shores. It would "therefore deftroy the mountains, and "form new ones of the fpoils thus worn away and depofited in its own bofom. "The fea accordingly began by de"molishing the primary mountains, the "wrecks of which were precipitated "to the bottom. Thefe wrecks then form the firft ftratum, which lies im"mediately over the primary moun"tains. In the language of miners, "I call this ftratum the red fol mort, "because there is a great deal of red "coloured matter in its compofition; "because it forms the bafis of many "other, perhaps of all other ftrata; "because it is perfectly ufelefs, and in fome measure dead as to metals. "This ftratum is compofed of a vast quantity of rounded ftones, aggluti"nated together by a red or grey arແ gillaceous fubftance, and the whole "has acquired a confiderable degree "of hardnefs. There is never found "in its compofition any fpecies of "stone which we can fuppofe to have "been formed pofterior to itself. We "always obferve in it the parts and "productions of primary mountains, "efpecially of thofe that most abound "in the neighbourhood. I would confi"der it as a great curiosity, if any one "could fhew me in this ftratum any gypfum, marle, fetid ftone, &c. But "it is not eafy, however, to explain, why no marine bodies petrified are ever found in this kind of stone. "Perhaps, by the immenfe quantity "of hard ftones, which would be rol"led and jumbled at the bottom of "the fea, they might be broken be"fore they could be agglutinated to"gether. But we find, and particu"larly at Kifthauferberg, entire trunks "of trees petrified, which is a proof " that there had at that time been ve"getation on the globe, before the 46 66 The ftratum we have now been fpeaking of has been formed fimply by precipitation, as it is found only horizontal, where it had a bottom to reft upon; the following ftrata have been formed under water rather by attraction or incruftation, for they may be found of equal thickness upon the fides of the primary mountains, where they are almoft perpendicular, as in other places where they are level; in fhort, they appear to have been formed as the cruft on the infide of a kettle, or the tartar in wine cafks, equally thick and ftrong on the fides as at the bottom of the veffel. Thirteen of thefe fecondary ftrata are enumerated besides the fol mort ; but all of them are not always to be found in the fame place, nor do they preferve any regularity in the order of their fucceflion. They are grey compact lime-ftone, mixed with clay, gypfum, fetid-ftone, fand-stone; clay mixed with fand, lime-ftone, oolites, clay, pit-coal, argillaceous fchift, bituminous wood, and fal gem. But the most remarkable is a fchif tus of a blueish black colour, like common flate, though the conftituent parts are very different, being calcareous, argillaceous, and bituminous, often containing filver, copper, lead and fulphur. It is called by the miners, the copper fchift, or fireb; it lies immediately above the fol mort, or fometimes parallel to the fide of the primary mountain, even where this is vertical; as in the pit of St John, where it has been followed to the depth of 150 fathoms, and then it becomes nearly horizontal like all the ftrata of this kind. The author does not forget a fact that proves clearly the revolutions which our globe has undergone. This is called the troubles, (fauts des couches.) "It appears, he fays, that the ftra"ta have been broken after their for"mation in different places, and that "the great fragments have been forced "from their place. If you will figure "to yourself certain ftrata laid over "one another, and broken by a vertical "fiffure, and that one fide or edge "of the whole mafs has funk down "below the other, you will have "the idea of these troubles. When, "for example, we find over the fol "mort, which fuch a fubverfion has "funk five feet lower, one of the "fides of the mass of these strata, we "are certain that all the fuperior ftra"ta have been affected with the fame "accident, and that it has made its ແ way upwards, the length of the vege" table foil. "It often happens that fragments "of the different ftrata remain in these "fiffures; but the interftices have "been gradually filled up by new pro"ductions, which the miners are al"ways overjoyed to find; for they procure from them most frequently "cobalt, different kinds of ores of copper, and stones which are not "common in ftratified mountains. "Thefe troubles are almost the only "places where the ores at Groffen "camfdorf in the canton of Saalfeld, "and other places are found. Al"though the fiffures which have pro"duced them extend to a very con"fiderable depth, they are only pro "fitable to miners, between the ftra"tum of schift and the place where "the mountain has funk. Below that " or above it, they are generally fte"rile. Some even fuppofe that the "fiffures we are talking of may be "owing to the original very angulated "form of the primary mountains on "which the strata have refted. But "in that cafe, none of the fiffures "would have contained minerals, and "there would have been horizontal, "as well as vertical troubles. "It is difficult to account for thefe "feparations. It appears probable to "me, that they have been formed "when our volcanoes were still burn"ing, and when they were raised out "of the bofom of the earth." M. Voigt then proceeds to give his opinion of thofe detached pieces of granite, lapis cornes, porphyry, quartz, &c. which are fo frequently found lying at a great diftance from any hill of the fame fubftance, and are found not only on plains, but of ten blocks of them a confiderable way up hills, in countries not very high. Thefe he thinks may have been tranfported to this diftance by being im bedded in pieces of ice while the waters covered the country: it is a wellknown fact, he alledges, that pieces of funk wood are often raised from the bottom of lakes, by a congelation which takes place at the bottom, inclofes the wood, and afterwards rifes and floats with it to the shores. An old fisherman, at a lake not far from Keil, declared it was a common thing to fee large pieces of granite, &c. brought up in the fame manner from the bottom every winter, and thus great numbers of them were fometimes collected on the fhore. A gentleman of profound know. ledge in the theory of mountains, in a letter to M. Voigt, expreffes himfelf of a different opinion, on the fubject of these transported pieces of primitive ftones, fcattered here and there on the plains, and on the fecondary ftratified hills. ર "It is certain, fays he, that these "ftones have come to the places where "they at prefent lye, either from a "bove downwards, or from below up, "wards. If you admit the last hy"pothefis, then no doubt there is a "neceflity for finding machines to raise "them. You do not allow the fe "cond hypothesis, which would make "the effect proceed from an inunda"tion, because you suppose, that af"ter the retiring of the waters of the "fea, it was impoffible that any other "innndations could happen, fufficient "ly "ly powerful to carry along maffes "of fuch enormous bulk as fome of "those we often find. But if fuch an "effect could not follow from inun "dations, how could pieces, or even "mountains of ice perform it? Ac"cording to the principles of me"chanics, the firft caufe is infinitely "more probable than the other. "grees, but fuddenly, by fome great "In my opinion, this phenomenon "might have happened in the follow"ing manner: After the fubfidence "of the waters of the fea, the furface "of our fecondary mountains would "be left uncovered. Thefe mountains in conformity with the laws of depofition and attraction, were "formed in contiguous beds along the "chain of the primary mountains, "that is, on the fides of thefe moun"tains, and in the vallies between " them. The bottom of the ancient "ocean was higher by fome hundred "yards, than the bases of the fecondary "mountains, which are now habi"table. At that period they appeared "That the atmosphere would have "not as we now fee them, mountains "an extraordinary motion, after a great "and vallies, for thefe are the operation convulfion, the nature of things leads "of rivers. The collections of matter "us at once to believe. But of this we "which the fea has made in different "might bring an obvious, if not a "plaçes feem very inconfiderable, " mathematical demonftration. The "when from the top of fecondary "breadth of the beds formed at first "mountains we confider their ancient" by the waters of rivers was equal "level. The waters of the atmosphere "to the diftance between the tops of "precipitated themfelves in all direc- "two oppofite mountains; and their "tions, from the top of the primary "depth was from the tops to thofe on the fides of the fecondary moun- "plains which we find near any con"tains, and forced along with them "fiderable river, which makes about "whatever they met with. But thefe "one third of the height of the whole "waters must have hollowed out chan- "mountain, more or lefs, according "nels, and formed for themfelves par- as it is compofed of lime-ftone or "ticular beds. The fhortnefs of the "fand-ftone; for, in the firft, the par"interval is, in my opinion, the caufe "ticles of matter cohere together "why we do not more frequently find "more firmly than in the fecond, "fuch detached fragments of the pri- "Hence, in lime-ftone mountains mary mountains on the fecondary, "the declivities are more abrupt "and that they are always fingle and " and the vallies narrower; while in "difperfed. "thofe of fand-stone they are much "wider. 66 86 66 "I must obferve, in paffing, that "this circumftance feems favourable "to the opinion of thofe who imagine" "that the fea did not retire by de "In comparing thefe dimenfions of the ancient bed of a river, we 06 may calculate how many cubic feet ." it "it originally contained. Let us confider thofe thread-like ftreams which "we now dignify with the name of "Rivers; let us examine the ravages "that even at this day are occafioned "by inundations, and then from the "cause if we infer the effect, we will "have no difficulty in conceiving the "force of the waters at that early pe❝riod. "broader and deeper the valley, the "more force would the ancient wa"ters have to carry along with them "thofe immenfe detached maffes of "the diftant granitical mountains. "The caufe is always equal to the "effect. Such detached maffes are "often carried down even by rivers, "not by the waters of the atmosphere, "of which I have been speaking, to "places where we would never pre"fume that thefe rivers had ever been, "and from which they are diftant fe"veral leagues. This is chiefly ob"fervable in the places where the tor "rent would exert its utmost force. "There the mountains are generally "lower than on the oppofite places. "The current has divided itself into lakes around it. Thefe are the very 66 two arms, and formed an island "circumstances that shew how it must "which has become a mountain se"have been transported. The higher parate and detached, and the arm "a fecondary mountain is, the nearer" that took a direction distant from the "it is to a primary mountain, and the " principal current, no longer exifts." "Meiners faw a mass of granite of "the weight of many thousand tons "on the most elevated part of Mount “Jura, which is a mountain of calca*reous matter. He was not able to "conceive how that prodigious rock "had been placed there, confidering "the height of the mountain, and the "depth and extent of the vallies and 66 Account of a Moving Bog in Ireland. A CORRESPONDER fee the Bog of Monaghan, and Liflowrin, near Dundrum, which has caufed fo much converfation, and created fuch alarm in that neighbourhood, has given us the following account of this extraordinary phenome non : "On the 27th of March laft, a rumbling noise from the bogs attracted the attention of the furrounding inhabitants, who abferved the bog to be much agitated; both the noife and agitation continued to the 30th, when they were greatly increafed; the furface gave way at the fouth-eaft fide of the bog, and a prodigious quantity of matter iffued, taking its courfe in the above direction, towards Ballygriffin, and Golden, overfpreading and laying waste a very fine tract of country. "The groffer part of the matter is fhoved at each side of the channel thro' which the more fluid part takes its ed a barrier to the channel; which, from the fource to the extremity of the lava, is invariably in the centre of the matter difcharged. The breadth of this ftratum, in fundry places, is nearly an English mile, in other parts is very narrow. "Our correfpondent accounts for this extraordinary event in the followmanner; he fays, the bog is from two to three miles in diameter, furrounded by high grounds on all fides, except where the lava iffues, and in one place more at the oppofite fide of the bog. He is of opinion,that the bog itfelf has been originally formed by the defluxion from thofe high furrounding grounds,and that the conftant diftillation has continued, ever fince its first formation, to increase and elevate the bog; that time had given to the furface, not only strength and toughness, but an elafticity which accommodated itfelf to the gradual in flux flux from the furrounding hills, whereby the bog has been raised to an elevation vastly above the furface over which the lava is now flowing, notwithstanding which the texture of the furface was fuch, that it confined the internal matter, though the centre of the bog had arifen many yards above the level of the two paffes already mentioned. "Every thing that oppofed its progrefs was buried in ruins. Four houfes were totally deftroyed, and feveral ditches, croffing the valley through which it flowed, have been proftrated, and the trees growing thereon fwept away, nothing being able to refift its impétuofity. The discharge has been inceffant fince the 30th, and how far it will extend feems difficult to determine; it has already croffed the great road leading from Dundrum to Cashel, rendering the fame quite impaffable; it has come to within half a mile of Ballygriffin-bridge, and in its progrefs has not covered lefs than between three and four hundred acres of excellent ground; part of the eftate of John Lapp Judkin, Efq; of Cafhel, and part the estate of Col. Hyde.-The distance from Ballygriffin to Golden is not more than a mile, the paffage is narrow, and the fall very confiderable; fo that, unless the discharge from the bog fhall fpeedily ceafe, the confequences to be apprehended are ferious and alarming; and from the reafons given hereafter, there feems no profpect of any ftay to the iffuing of mater from the fource. The quantity of matter at prefent coming down the country, appears too great for the river Suir to carry off; fhould the lava reach that river (which is very probable) and prove an over-match for its force, the country must be inundated, and the river diverted from its prefent channel. The matter iffued from the bog is a black turf mould, of the confiftence of thick porridge or ftirabout, carrying with it large pieces of the furface of the bog, which have fallen in to the current. "The progrefs of this matter is generally very flow and progreffive, which is proveable from the advance it has made fince the 30th, being about two miles and an half from the fource. At particular periods, however, the lava iffues with extraordinary rapidity, owing to a junction of the difmembered furface in the neck of the bog,. which becomes a temporary obftruction to the discharge; but, as foon as the flowing matter forces through this obftruction, the motion is vaftly in creased, and the matter runs at the rate of fix or eight miles an hour. At thofe feafons of agitation it undulates like the fea; and if any thing oppofes its progrefs, it becomes furious, and emits a fpray to a height of several yards. The ftratum which covers the plains through which it paffes, is broad and narrow according to the fituation of the ground through which it runs ; its depth is alfo various, owing to the fame caufe, in fome places not more than two feet, in others from fix to ten. "On this principle, if we confider the long continuance of rain we have had during the past winter, and the vast quantity that must have concentered in a spot fituated as this is, we shall eafily conceive that fuch a body of water, filtered through the furface, and mixing with the inclofed matter, not only increafed and agitated it, but proved a furcharge too great for the furface to contain, which at length burst, and thus the interior matter found its way into the adjacent country. Notwithstanding the centre of the bog is confiderably funken, and every perch of it is feparated by a fiffure, the elevation is ftill many yards higher than the channel through which the lava iffues, and it is more than probable, a much greater quantity of matter remains to be discharged than what has yet been emitted." On the whole, this is confidered to be one of the most curious circumstances in the hiftory of nature this kingdom has furnished for many ages paft. Account |