CHAPTER II.THE PERMIAN SYSTEM—NEW RED SANDSTONE.
The geological formations described are succeeded in the ascending order by thePermiansystem of deposits—a term borrowed from the department of Perm in Russia, where the strata cover an area about twice the size of France. This constitutes the new red sandstone of English geology, and has many equivalents in other countries. Thus, in the lower division of the group or true Permian, there occurs the Zechstein and Lower Bunter series of strata: in the upper or triassic division, the equivalents are the Upper Bunter and Grés Bigarré, or variegated sandstone, the Muschelkalk and Keuper of French and German authors. The system is largely developed in America, Africa, India and China; where, as in Britain, the deposits are of extremely varied mineral characters, consisting of grits, sandstones, marls, limestones, gypsum, and rock-salt, each presenting its own family types of vegetable and animal life.
The new red sandstone extends across England without interruption, through the medial or central counties, and ranges nearly north-east by south-west. The two great divisions of which it consists are everywhere well marked, the dolomitic or magnesian limestone forming the base, and giving character to the lower permian group; the upper triassic group is sufficiently distinguished by the rock-salt deposit which is wholly included in this part of the formation. Each, too, has its own peculiar set of fossils. Those of the former are allied to animals that flourished during the carboniferous period; two genera of fishes, the palæoniscus and pylopterus, are common to both. The fauna and flora of the triassic group are regarded as entirely new, neither borrowing from nor imparting anything to illustrate theorganisms of the older families of rocks. The one series of strata thus represents the coming of a new, the other records the departure of a past state of things.
In the central counties of England this deposit expands into a great plain, surrounded on all sides by the coal-measures, while within its own area several basins—as those of Leicester, Warwick, and South Stafford—are included, being completely isolated by the new red. An interesting economic question hence arises—Do the coal minerals occupy the whole or any considerable portion, of the extensive area covered by this formation? An equally important geological problem is connected with the solution of the question—namely, What are the general relations of the older to the newer deposits of the district? The researches of Sir R. I. Murchison, and more recently, of the geological survey, have shown that the three groups of stratified rocks in South Staffordshire, the new red sandstone, coal-measures, and silurian beds, are each unconformable to the other—that the upper rests indifferently upon the two lower formations—and that where the old red occurs, the new is sometimes in immediate contact. It is inferred from this, that there was an uplifting of the silurian rocks, along with considerable denudation, previous to the deposition of the carboniferous strata. Mr. Jukes has observed pebbles of coal, in great abundance, in the lower beds of the new red sandstone, and thence deduces the following conclusions:—1. That there was a movement and denudation of the coal-measures, amounting, in some localities, to their entire destruction and removal, before the deposition of the new red sandstone. 2. That, subsequently to the deposition of the new red sandstone, there was a very great movement of all these rocks, producing their present faults and inclined positions. 3. That the boundaries of the South Staffordshire coal-field, as far as examined, present examples of three kinds of relation between the coal-measures and new red sandstones;i. e., by conformable succession; by fault, the coal-measures being present on the downcast side; and, thirdly, where the destruction of the coal-measures has brought the new red sandstone into immediate contact with the silurian strata. The author of this paper is farther of opinion that, while there is a great probability that the larger part of the new redsandstone plain conceals productive coal-measures, there is the presumption that these will not be found at a depth of less than 500 or 600 yards below the surface.
Corresponding with these views it will be remembered that, after the deposition of the coal-measures, there succeeded a period of violent plutonic action, whereby the formation was dislocated, broken up into smaller sections or basins, and pierced by the igneous rocks. There would, consequently, during this season of paroxysm, be a vast destruction of animal and vegetable life. The indurated crust would everywhere undergo great trituration. Gravel, sand, and mud of every quality would be cast along the shores, or silted up in the deeper hollows. And then again would come a term of general repose, as the angry elements subsided, exhausted by their own violence. The scene was actually or nearly as described; and, in the aspect of the older denuded and uplifted rocks, as above represented, there are the most striking evidences of the agitations of the period. The exuberant flora of the carboniferous age, suffered prodigiously, or became utterly extinct. Conglomerates were formed which exhibit few traces of organic life. To these succeeded the vast areas of the fine-grained sandstones, and gypseous and saliferous marls, everywhere nearly horizontal, and still undisturbed on their ancient beds. The tribes of animals were abridged in numbers, changed or modified in structure, so as to suit the altered state of things. The rain-drop, ripple-mark, and foot-print are all witnesses to be adduced of the mighty change, as they are all proofs of the doings of Him who holds the waters in the hollow of his hand, makes the clouds to distill in showers, issues his command to the hurricane and the earthquake, and restores in renovated beauty the face of nature.
The lowest bed of the formation is the magnesian limestone, which derives its name from the quantity of carbonate of magnesia distributed through the matter of the rock, amounting in some instances to as much as sixty per cent. It is likewise called thedolomiticlimestone, from M. Dolomieu, who first investigated its granular crystalline structure. This limestone is generally of a yellow color, glimmering luster, passing occasionally into blue and brick-red varieties, and exfoliates in thin plates, or breaks upin large botryoidal masses. In this form it occurs at the cliffs of Durham, where it assumes the grouping and arrangement of chain-shot; and, as the beds are distinctly stratified, the face of the rock has a very striking and pleasing effect. In the more southern counties, this formation exists generally in the form of a conglomerate, supposed to be derived from the debris of the older carboniferous limestone united by a dolomitic paste; thus illustrating the source and mode of the deposit, while in the organic remains there has been traced a regular gradation between the types of the older sub-carboniferous and the successive newer strata.
Let us consider some of the more remarkable forms, tracings, and ingredients of the formation.
I.The Organic Remainsare scanty as compared with those of the age immediately anterior. The vegetable forms, as yet detected, are new and distinct. The fishes consist of six or seven genera, and about as many different species. And here commences, it is supposed, the singular change in their ossification, for which science can assign no reason, as it cannot detect the least appearance of graduation into the new, for the first time, begun and completed change. The fishes of the formation present theHomocercal—that is, the equally-lobed, or one-lobed tail-fin,—a structure peculiar to existing races, with the exception of the shark, sturgeon, and a few others, and form a striking contrast to those in the antecedent groups, which were all possessed of theHeterocercal, or unequally-lobed tail-fin.
Heterocercal. Homocercal.
Heterocercal. Homocercal.
Heterocercal. Homocercal.
The Permian system of strata has hitherto been noted for the introduction of walking, air-breathing animals; hence it has beena canon of the science, that in these deposits lie entombed the last links of that ancient chain of organic life which prevailed from the beginning, and also the first terms of the new series which attained to such monstrosities and prolific exuberance in the succeeding epoch. Doubtful as to the existence of reptilian and ornithic creatures during the carboniferous period, both forms of creation are here distinctly manifested; and, in the higher members of the triassic group, birds and reptiles have left traces of their path. Thus remarkably defined, in an invariable chronological series, was the new red sandstone formation; all the ancient types of organic life were disappearing; completely new forms had just begun to replace them. But, while we are writing, the discovery has been announced that, so old as the devonian age, reptiles existed; alligator-like foot-prints, in regular alternating order, have been found impressed in the old red sandstone, near Pottsville in Pennsylvania, and by Mr. Lea, their discoverer and American conchologist, the animal which owned them has been named theSauropus Primævus. A revolution in geology is decreed in the words. Many divisions in the systems of rocks will have to be revised, many distinctions altogether obliterated, theories of development and of many other things are now sadly misplaced, and out of keeping with the newly-declared order and progress of organic life.[7]
But without venturing at present to enter upon the consequences to palæontology involved in this important discovery, we proceed with the known and recognized history of the formation in question.
The organic remains contained in the upper, or triassic group, differ considerably from those of the lower division of beds.—While the same families of vegetable fossils are preserved which characterized the coal-measures, the particular species and genera have disappeared. About twenty species of ferns and coniferæ, a few calamites, several fucoid plants, and a gigantic genus namedVoltzia, and resembling the Araucaria or Norfolk Island fir, comprise the thinly-scattered specimens of the flora of the period. The quarries at Coventry yield some undetermined stems of trees, and leaves like those of our thick-ribbed cabbages have been found in the strata near Liverpool. The animal remains are more numerous as well as varied in their structures; some, indeed, altogether anomalous in their organization, and foot-prints of the most puzzling characters and dimensions. There are several new types of mollusca and crinoidea, among the latter theEncrinus formosus, one of the most beautiful forms in any department of the animal kingdom. The fishes of the placoid order consist of seven genera and fourteen species, of ganoids three genera and seven species. Thereptiliasupply the marvels of the period.Prof. Owen has described six distinct genera from these singular fossils, in which he has established an affinity to the batrachia. From the curiously-complicated texture of the teeth, the termlabyrinthodonhas been given to one genus, while the same authority suggests, that the foot-impressions to which the termcheirotheriumhad already been applied, might belong to this animal. The two genera,claydyodonandrhyncosaurus, are remarkable specimens of organic structure, the latter combining the lacertian type of skull, with edentulous jaws, which impart to the forepart of the head the profile of a parrot.
II. TheIchnolites, or foot-prints, constitute a marked feature of the formation. These geological phenomena were first introduced to the notice of the public, about twenty years ago, by the late Dr. Duncan of Ruthwell, when his announcement of the tracks and foot-marks of animals along the ancient shores of Dumfries-shire created a sensation among all classes hitherto unprecedented in the history of the fossil department of the science. Robinson Crusoe was not more moved at the discovery of a human foot-print on the sands of his lonely island in the distant main, than were men of science, that traces of organic life should thus be stereotyped in a deposit believed to be utterly destitute of fossil relics. The creatures which had traced them, so like to existing walking things, greatly increased the interest and the wonder excited by the picture—the tread in all the freshness of yesterday of the inhabitants of the antediluvian world! The phenomenon, however, is now one of very general and common occurrence, several quarries in the same locality—various places in England—in Saxony—in the states of Connecticut, Massachusetts, and Virginia—having since been found to yield the impressions in the greatest abundance, and of numerous types and forms. And so well delineated and perfect are the impressions, that, in the absence of any other reminiscence of the animal, these characters have supplied the same aid to the skillful palæontologist that the fragment of a bone, a fin, or a scale, did to Cuvier and Agassiz, in the reconstruction of their organic models, and determination of extinct genera and species. Birds and reptilian quadrupeds have all contributed their share in the production of these curiouslithographs. Small toe-looking scratches, deep-palmy impressions, cloven hoof-like indentations, and large gigantic hollows, have all been pictured in clear distinct outline, covered up, and now again laid patent before you as by the removal of the coverlit of your album. The Boston “Journal of Natural History” communicates the following interesting account of the researches of Dr. Deane:—“I have in my possession,” he says, “consecutive impressions of tridactyle feet, which measure eighteen inches in length, by fourteen in breadth, between the extremities of the lateral toes. Each footstep will hold half a gallon of water, and the stride is four feet. The original bird must have been four or five times larger than the African ostrich, and therefore could not have weighed less than 600 pounds. Every step the creature took sank deep, and the substrata bent beneath the enormous load. If an ox walk over stiffened clay, he would not sink so deeply as did this tremendous bird.” Sir C. Lyell has examined most of the foot-print districts in America, and found the markings so numerous in some places as to resemble the puddled stand of a sheep-fold or market-place; the very spots, doubtless, whither the animals had resorted to quench their thirst, or screen them at mid-day from the scorching heat. The various tracings become more distinct in proportion to the distance from the scene of common rendezvous, and the several routes by which they would return to their respective haunts, or fields of pasturage, are clearly defined.
A considerable doubt hung over the accounts from time to time detailed in the American journals and other publications, concerning these novel and extraordinary discoveries, until they were more than matched by the actual exhumation of the entire skeletons of the feathery tribes, far exceeding in dimensions anything hitherto dreamed of in the science of ornithology. The collections of Mr. Williams, and of Mr. W. Mantell, from the alluvial deposits of New Zealand, utterly confounded all previous calculations as to the size and bulk attainable by the bird tribe. The tibia of a Dinornis, in the collection of the University of Edinburgh, measures thirty-one inches in length, a femur seventeen inches, the average circumference of both being nearly twelve inches. From the foot to the top of the clavicle, the animal must have stood at least thirteen feet in height. With the strut of the turkey, or the pride ofthe peacock—head and neck of corresponding altitude—what a denizen for the wilds and forests of this region of the new world! When animals of similar dimensions, but of an earlier epoch, frequented the beaches of Great Britain, we have to imagine the Cumbrian mountains, the Penine chain, Derby Peak, and the lofty cliffs of Avon, surrounded by an inland sea stretching by central France, the Black Forest, and the Hartz mountains, and the shores all round silted with the materials which now constitute the triassic group. Tortoises, turtles, bird-headed lizards, birds themselves, salamander and frog-like creatures larger than crocodiles, resorted as now to the sea-shore, in the cool fresh of the evening or as tide-mark permitted, and regaled themselves at will on the food which an ever-bounteous element furnished to their various wants.
The science which, from suchindiciaas these, has succeeded in determining not only the class, but the very form and habits, of the animals which impressed them—no other traces remaining than those petrified footsteps, covered up and hidden for ages—presents subjects of study to the inquiring mind, which may well rank among the most valuable, as well as curious, of human research. Is it not wonderful enough, that organic impressions merely should have been transmitted so fresh and entire, as to admit of classification, equal in scientific precision to that of the families of living things? What matter of suggestive reflection, inscribed on every page of that history? The tribes which were created and flourished during the Permian-triassic age perished, their earthy parts in most cases were all again absorbed by the earth, dissipated or melted into the viewless air. Still there are memorials of their existence, enduring and indelible, not of bones and sinews, but of actions and habits, which the waters cannot obliterate, nor the floods wash away! Man, a being of a different mold,—and with him
“Will all great Neptune’s ocean wash this bloodClean from my hand?”
“Will all great Neptune’s ocean wash this bloodClean from my hand?”
“Will all great Neptune’s ocean wash this bloodClean from my hand?”
“Will all great Neptune’s ocean wash this blood
Clean from my hand?”
was the cry of instinctive dread—the foreboding of an assured conscience, that the foul and guilty deed could never be effaced from the memory, nor blotted from the records of creation.The foot-tread of the robber has tracked him to his den; the minutest stain of blood has established the crime of murder; a dream or vision of the night has pointed to the mangled corse; a word uttered years after all was forgotten, or a rude ditty chanted, have recalled the pictures of infancy, and the wanderer to his home. Here we behold, stamped upon the rock, legible as the law upon the tablets of the heart, intimations of the great universal law, that an act once committed cannot be canceled; that a cause will be followed by a sequence of effects; indefinite and ever-extending; and that the Divine Spirit, which drew illustrations from the fields and taught wisdom among the rocks of Horeb, still points the moral in these ineffaceable memorials—that the recording angel so traces in the book of life the story of every age, of every generation, of every individual, never to be lost nor forgotten in that eternity whither their works do all follow them.
III. Other singular records of the age under review have been preserved in a similar manner; for the ocean itself has not failed to impress its own movements on the sands laved by its waters. Hence theripple-markhas been detected, a recognized object of the science, and a phenomenon to be seen in the sandstones of all ages and in all countries. The new red, from the stiller waters perhaps in which it was formed, contains everywhere beautifully minute and perfect delineations of the kind. Thefurrowedsandstones form a class by themselves, being selected in the neighborhood of Brighton, as paving-stones for the streets, and in the stable-yards as a protection for the horses against slipping. The traces often of the more destructive violence of the sea, even of recent date, in leveling villages, sweeping down plains, undermining cliffs, overwhelming proud navies, are completely obliterated or forgotten, while here the records of its still voice are indelibly engraven on the rock.
Observe other markings as you walk along the sea-shore on a summer’s eve; how every wavelet that breaks upon the beach leaves its tiny indentation, until the whole surface becomes furrowed as the reflex of the ever-shifting flood; there spring up on every side innumerable hillocks of sand, little blisters through which you detect the movements of a creature within, and thenthe trail of the sea-worm is visible all over. These werevermesandannelidesburrowing in the sands, in those ancient times, with instincts and habits precisely the same. “We find,” says Dr. Buckland, “on the surface of slabs, both of the calcareous grit, and Stonesfield slate, near Oxford, and on sandstones of the Wealden formation, in Sussex and Dorsetshire, perfectly-preserved and petrified castings of marine worms, at the upper extremity of holes bored by them in the sand, while it was yet soft at the bottom of the water; and within the sandstones, traces of tubular holes in which the worms resided.” Nature here has changed little from her first models; the same element, which is now chaffing upon the same materials of sand and rock, has possessed through all time the same ingredients of life-stirring action.
IV. Nor has the atmosphere—that twin ocean of upper earth—failed to give evidence of the properties and laws by which it was then governed. Therain-drop, a singular unmistakeable marking, has also been detected upon the sandstones of the period. These impressions have been described and adopted by men of science as the true veritable indices of the showers and cloud-falls of the old world. The very size of the drop may be measured, the thick pattering of the rain compared with the scanty or copious showers of the present day, and the very point detected from which the wind blew on the day that these showers fell. What a curious tale is thus disclosed, by a record, no modern version of which any one will stay to read a moment longer than he can escape to shelter from its influences. Astronomers tell us, upon the faith of the Herschels, the measurements of Strüve, Bessel, and Mädler, that, notwithstanding that light travels at the inconceivable speed of two hundred and thirteen thousand miles in a second, the light from Uranus, one of our own planetary system, does not reach our earth until two hours after it has been emitted from its orb; that, from the edge of the Milky Way, a star of the twelfth magnitude, careering in all the effulgence of that luminous ether, cannot be descried until four thousand years after the ray has begun its journeyings; and yet more, as the results of the most rigid induction, it is revealed to us that the spots of clouds, which under the resolving power of the best telescopes seem moreoval flakes or small specks of whiteness, are really distinct and independent systems, floating at such an immeasurable distance that the light has to wander millions of years before it can break in its faintest morning-streak upon our horizon. Mark the analogy, therefore, ere you scoff at the credulity of the geologist, or the power of the rain-drop to transmit an image of itself through so many revolutions and ages of the earth’s history. How impalpable a substance is light! how readily effaced its impressions, or intercepted its brilliant colorings, by the interposition of the frailest creation of matter—an insect’s wing, the covering of a leaf, the disc of a flower-petal. But the light, thus easily obliterated or dimmed on earth, has been maintaining its own solitary independent course through every medium, every change, of upper and netherworlds. The moment of its efflux from remotest orb, in depth of infinite space, gave to every particle of that feebly or intensely luminous beam, a separate being and direction, with no return back to its parent source. And now, says the intelligent astronomer, as it drops gently into the searcher of his telescope, that is a ray from yon far distant unresolvable cluster of stars, or of astral systems, for millions of years traveling through these incalculable heights, when as yet the Chaldee sages had pointed no instrument to the heavens, nor the learned of Memphis recorded an observation. Can you deny to other matter, argues the geologist, a similar tenacity of self-preservation, the vitality of impress which merely records the uniformity of the laws and constitution of nature, and which intimates that, through all past time, there were showers to cheer and to refresh the products of the earth? Truth becomes more marvelous than fiction when traced in researches such as these—showing the illimitable range over time and space permitted to human inquiry—and producing, at the same time, things both of heaven and of earth scarcely to be dreamt of in human philosophy.
V. But the economic and practically useful, no less than the speculative or fanciful, form constituents of the new red sandstone formation. The strata are not only indented with impressions of strange and doubtful origin; they inclose, like those of the carboniferous system, treasures of the greatest value; and nature,in ceasing to abound in one kind of product, has been no less exuberant in others, equally contributive to the comfort and convenience of man. In this class of rocks are situated our great deposits ofrock-saltand gypsum, of the former of which, beside supplying the demands of the home market, the mines of Cheshire alone export from Liverpool upward of half a million of tons weight. The distribution of the saline mineral is very general over the earth, and by no means constant in its geognostic position; as, for example, in Galicia, it is found among the tertiary deposits; in New York, it occupies the middle of the silurians; while in Hungary, Poland, and England, it is uniformly associated with the new red sandstone. Rock-salt has been long known to and prized by mankind; it became an object of taxation or tribute six hundred and forty years before the Christian era, as narrated of Ancus Martins, “salinarum vectigal instituit;” and hence centuries afterward, when Great Britain was in possession of the Romans, the legions received salt as part of their pay or “salary.” Our richest mines are in Cheshire, and along the districts watered by the Dee, the Weaver, and the Mersey. The beds, or rather masses, are imperfectly stratified, and vary in thickness from a few inches to 120 feet and upward: gypsum and variegated marls may be regarded asconstantsin the formation, the gypseous deposits sometimes attaining the enormous depth of 150 feet.
We speak of the beds of gypsum asdeposits, in common with those of the sandstone matrix in which they are imbedded. It appears, however, on inquiring into the theory of their origin, that they are not strictly such in the true sense of deposits—originally as gypseous deposits—but altered limestones, metamorphosed by the action of gases which have escaped from beneath, and permeated the calcareous mass. The carbonates of lime have been converted into the sulphates of lime, by means of gaseous emanations produced in unknown volcanic depths. Even the dolomitic member of the group is supposed to have a like metamorphic origin; the needful elementary agencies having entered into the parent limestone, and converted it into the magnesian type. Why nature should not have done these things directly, at the first off-throw, science could not, perhaps, very satisfactorily answer the skeptically inquiring mind; but, as the ingredients are all chemicallywell known, and more especially as there is a vast laboratory ever at work, filled with all kinds of elements, in her subterranean regions, any hypothesis of formation is as rapidly established as it is conceived, and the interest of the subject humanly speaking augmented. The celebrated Berzelius, when questioned on the point, had his ready solution of the problem, easily derived from his unparalleled stores of chemical knowledge:—“Give me a substance containing sulphur—admit the presence of the vapors of sulphur, or sulphurous or sulph-hydrous vapors,—let limestone be also present, and water on the surface or in the atmosphere,and we shall readily have gypsum.” The origin of the saltness of the ocean is still a mystery in science; equally involved in doubt and conjecture is that of the other member of the series, the rock-salt formation. The generally adopted theory, however, is, that it was dependent on volcanic agency for development, as it both contains, and is uniformly associated with, the acids, and other materials found in connection with volcanoes. The chlorides of sodium and gypsum, for example, are at present sublimed from volcanic vents; vapors charged with sulphuric acid are constantly issuing from the same sources; and these passing through or associated with the saline waters of the period, must have aided in the formation of rock-salt and gypsum, which occur more frequently in irregular masses than in true stratified deposits. An additional corroboration of the theory is inferred from the circumstance, that the gypsum accompanying the rock-salt is anhydrous, that is, free from water before exposure to the action of the atmosphere. Hence the conclusion, that the consolidation of both the rock-salt and the gypsum must have been effected by the agency of heat, as, by means of aqueous deposition, a hydrometric influence would have been sensibly perceived.
Wonderful certainly is all this—the inclosing, the consolidation, the arrangement of these remarkable substances. The sea, in the first instance, may readily and abundantly have supplied all the elements of the formation; but how collected and retained, crystallized and incrusted, layer upon layer, over the rocky bottom and volcanic inner chambers, are points still of nice geological inquiry. The celebrated salt mines of Cracow, in Poland, are wondrous operations of the art of man, into the still morewondrous products and recesses of nature. Here the entire arrangements of a city are almost perfected; the streets, marketplace, chapel, rivers, reservoirs, grottoes, and all the requirements of comfort and safety gleaming in a blaze of saline crystals.
“Scoop’d in the briny rock long streets extendTheir hoary course, and glittering domes ascend;Down the bright steeps, emerging into day,Impetuous fountains burst their headlong way,O’er milk-white vales in ivory channels spread,And wondering seek their subterraneous bed.Long lines of lusters pour their trembling rays,And the bright vault returns the mingled blaze.”
“Scoop’d in the briny rock long streets extendTheir hoary course, and glittering domes ascend;Down the bright steeps, emerging into day,Impetuous fountains burst their headlong way,O’er milk-white vales in ivory channels spread,And wondering seek their subterraneous bed.Long lines of lusters pour their trembling rays,And the bright vault returns the mingled blaze.”
“Scoop’d in the briny rock long streets extendTheir hoary course, and glittering domes ascend;Down the bright steeps, emerging into day,Impetuous fountains burst their headlong way,O’er milk-white vales in ivory channels spread,And wondering seek their subterraneous bed.Long lines of lusters pour their trembling rays,And the bright vault returns the mingled blaze.”
“Scoop’d in the briny rock long streets extend
Their hoary course, and glittering domes ascend;
Down the bright steeps, emerging into day,
Impetuous fountains burst their headlong way,
O’er milk-white vales in ivory channels spread,
And wondering seek their subterraneous bed.
Long lines of lusters pour their trembling rays,
And the bright vault returns the mingled blaze.”
The deposit near Cracow is worked on four different levels or stories, divided into innumerable compartments, with thousands of excavations in every direction, and descending to the vast depth of one thousand feet below the surface. The length of the several passages, in their windings and turnings, is calculated to be nearly three hundred miles; about two thousand men are constantly employed in the mining operations; and, though the operations have been carrying on for the known period at least of six hundred years, the mass of rock-salt in the locality is still of inexhaustible extent.
The mines in our own land are equally remarkable after their kind, and cannot fail to interest, if not to astonish, the neophyte who ventures a descent. From the mode in which they are worked, the huge pillars left to support the roof, the thousand lights that illuminate the caverns, the reverberations from the blasting which at intervals ring through their depths, a grandeur and impressiveness are imparted to a scene which scarcely any other combination of objects could produce. And another world—a world of coal and iron—in all its magnificence and riches, lies interred under these glistering stores of lime and salt! How strangely contrasting in their qualities and structure the two formations. But except that a wise and far-seeing Providence collected and garnered up the waste and decay of both for man’s use, no principle have we to guide us when speculating on their mineral properties and arrangement—no natural law certainly, self-acting upon matter and evolving new creations of its own, organic or inorganic, to reveal His inscrutable purposes.