An Excursion—The Chain of Crosses—Bay of Laig—Island of Rum—Description of the Island—Superstitions banished by pure Religion—Fossil Shells—Remarkable Oyster Bed—New species of Belemnite—Oölitic Shells—White Sandstone Precipices—Gigantic Petrified Mushrooms—"Christabel" in Stone—Musical Sand—Jabel Nakous, or Mountain of the Bell—Experiments of Travellers atJabel Nakous—Welsted's Account—Reg-Rawan, or the Moving Sand—The Musical Sounds inexplicable—Article on the subject in the North British Review.
An Excursion—The Chain of Crosses—Bay of Laig—Island of Rum—Description of the Island—Superstitions banished by pure Religion—Fossil Shells—Remarkable Oyster Bed—New species of Belemnite—Oölitic Shells—White Sandstone Precipices—Gigantic Petrified Mushrooms—"Christabel" in Stone—Musical Sand—Jabel Nakous, or Mountain of the Bell—Experiments of Travellers atJabel Nakous—Welsted's Account—Reg-Rawan, or the Moving Sand—The Musical Sounds inexplicable—Article on the subject in the North British Review.
Therehad been rain during the night; and when I first got on deck, a little after seven, a low stratum of mist, that completely enveloped the Scuir, and truncated both the eminence on which it stands and the opposite height, stretched like a ruler across the flat valley which indents so deeply the middle of the island. But the fogs melted away as the morning rose, and ere our breakfast was satisfactorily discussed, the last thin wreath had disappeared from around the columned front of the rock-tower of Eigg, and a powerful sun looked down on moist slopes and dank hollows, from which there arose in the calm a hazy vapor, that, while it softened the lower features of the landscape, left the bold outline relieved against a clear sky. Accompanied by our attendant of the previous day, bearing bag and hammer, we set out a little before eleven for the north-western side of the island, by a road which winds along the central hollow. My friend showed me as we went, that on the edge of an eminence, on which the traveller journeying westwards catches the last glimpse of the chapel of St. Donan, there had once been a rude cross erected, and another rude cross on an eminence on which he catches the last glimpse of thefirst; and that there had thus been a chain of stations formed from sea to sea, like the sights of a land-surveyor, from one of which a second could be seen, and a third from the second, till, last of all, the emphatically holy point of the island,—the burial-place of the old Culdee,—came full in view. The unsteady devotion, that journeyed, fancy-bound, along the heights, to gloat over a dead man's bones, had its clue to carry it on in a straight line. Its trail was on the ground; it glided snake-like from cross to cross, in quest of dust; and, without its finger-posts to guide it, would have wandered devious. It is surely a better devotion that, instead of thus creeping over the earth to a mouldy sepulchre, can at once launch into the sky, secure of finding Him who once arose from one. In less than an hour we were descending on the Bay of Laig, a semi-circular indentation of the coast, about a mile in length, and, where it opens to the main sea, nearly two miles in breadth; with the noble island of Rum rising high in front, like some vast breakwater; and a meniscus of comparatively level land, walled in behind by a semi-circular rampart of continuous precipice, sweeping round its shores. There are few finer scenes in the Hebrides than that furnished by this island bay and its picturesque accompaniments,—none that break more unexpectedly on the traveller who descends upon it from the east; and rarely has it been seen, to greater advantage than on the delicate day, so soft, and yet so sunshiny and clear, on which I paid it my first visit.
The island of Rum, with its abrupt sea-wall of rock, and its steep-pointed hills, that attain, immediately over the sea, an elevation of more than two thousand feet, loomed bold and high in the offing, some five miles away, but apparently much nearer. The four tall summits of the island rose clear against the sky like a group of pyramids; its lower slopes and precipices, variegated and relieved by gracefulalternations of light and shadow, and resting on their blue basement of sea, stood out with equal distinctness; but the entire middle space from end to end was hidden in a long horizontal stratum of gray cloud, edged atop with a lacing of silver. Such was the aspect of the noble breakwater in front. Fully two-thirds of the semi-circular rampart of rock which shuts in the crescent-shaped plain directly opposite lay in deep shadow; but the sun shone softly on the plain itself, brightening up many a dingy cottage, and many a green patch of corn; and the bay below stretched out, sparkling in the light. There is no part of the island so thickly inhabited as this flat meniscus. It is composed almost entirely of Oölitic rocks, and bears atop, especially where an ancient oyster-bed of great depth forms the subsoil, a kindly and fertile mould. The cottages lie in groups; and, save where a few bogs, which it would be no very difficult matter to drain, interpose their rough shag of dark green, and break the continuity, the plain around them waves with corn. Lying fair, green and populous within the sweep of its inaccessible rampart of rock, at least twice as lofty as the ramparts of Babylon of old, it reminds one of the suburbs of some ancient city lying embosomed, with all its dwellings and fields, within some roomy crescent of the city wall. We passed, ere we entered on the level, a steep-sided narrow dell, through which a small stream finds its way from the higher grounds, and which terminates at the upper end in an abrupt precipice, and a lofty but very slim cascade. "One of the few superstitions that still linger on the island," said my friend the minister, "is associated with that wild hollow. It is believed that shortly before a death takes place among the inhabitants, a tall withered female may be seen in the twilight, just yonder where the rocks open, washing a shroud in the stream. John, there, will perhaps tell you how she was spoken to on one occasion, byan over-bold, over-inquisitive islander, curious to know whose shroud she was preparing; and how she more than satisfied his curiosity, by telling him it was his own. It is a not uninteresting fact," added the minister, "that my poor people, since they have become more earnest about their religion, think very little about ghosts and spectres: their faith in the realities of the unseen world seems to have banished from their minds much of their old belief in its phantoms."
In the rude fences that separate from each other the little farms in this plain, we find frequent fragments of the oyster bed, hardened into a tolerably compact limestone. It is seen to most advantage, however, in some of the deeper cuttings in the fields, where the surrounding matrix exists merely as an incoherent shale; and the shells may be picked out as entire as when they lay, ages before, in the mud, which we still see retaining around them its original color. They are small, thin, triangular, much resembling in form some specimens of theOstrea deltoidea, but greatly less in size. The nearest resembling shell in Sowerby is theOstrea acuminata,—an oyster of the clay that underlies the great Oölite of Bath. Few of the shells exceed an inch and a half in length, and the majority fall short of an inch. What they lack in bulk, however, they make up in number. They are massed as thickly together, to the depth of several feet, as shells on the heap at the door of a Newhaven fisherman, and extend over many acres. Where they lie open we can still detect the triangular disc of the hinge, with the single impression of the abductor muscle; and the foliaceous character of the shell remains in most instances as distinct as if it had undergone no mineral change. I have seen nowhere in Scotland, among the secondary formations, so unequivocal an oyster-bed; nor do such beds seem to be at all common in formations older than the Tertiary in England, though the oyster itself is sufficiently so. We findMantell stating, in his recent work ("Medals of Creation"), after first describing an immense oyster bed of the London Basin, that underlies the city (for what is now London was once an oyster-bed), that in the chalk below, though it contains several species of Ostrea, the shells are diffused promiscuously throughout the general mass. Leaving, however, these oysters of the Oölite, which never net inclosed nor drag disturbed, though they must have formed the food of many an extinct order of fish,—mayhap reptile,—we pass on in a south-western direction, descending in the geological scale as we go, until we reach the southern side of the Bay of Laig. And there, far below tide-mark, we find a dark-colored argillaceous shale of the Lias, greatly obscured by boulders of trap,—the only deposit of the Liasic formation in the island.
A line of trap-hills that rises along the shore seems as if it had strewed half its materials over the beach. The rugged blocks lie thick as stones in a causeway, down to the line of low ebb,—memorials of a time when the surf dashed against the shattered bases of the trap-hills, now elevated considerably beyond its reach; and we can catch but partial glimpses of the shale below. Wherever access to it can be had, we find it richly fossiliferous; but its organisms, with the exception of its Belemnites, are very imperfectly preserved. I dug up from under the trap-blocks some of the common Liasic Ammonites of the north-eastern coast of Scotland, a few of the septa of a large Nautilus, broken pieces of wood, and half-effaced casts of what seems a branched coral; but only minute portions of the shells have been converted into stone; here and there a few chambers in the whorls of an Ammonite or Nautilus, though the outline of the entire organism lies impressed in the shale; and the ligneous and polyparious fossils we find in a still greater state of decay. The Belemnite alone, asis common with this robust fossil,—so often the sole survivor of its many contemporaries,—has preserved its structure entire. I disinterred from the shale good specimens of the Belemnitesulcatusand Belemniteelongatus, and found, detached on the surface of the bed, a fragment of a singularly large Belemnite, a full inch and a quarter in diameter, the species of which I could not determine.
Returning by the track we came, we reach the bottom of the bay, which we find much obscured with sand and shingle; and pass northwards along its side, under a range of low sandstone precipices, with interposing grassy slopes, in which the fertile Oölitic meniscus descends to the beach. The sandstone, white and soft, and occurring in thick beds, much resembles that of the Oölite of Sutherland. We detect in it few traces of fossils; now and then a carbonaceous marking, and now and then what seems a thin vein of coal, but which proves to be merely the bark of some woody stem, converted into a glossy bituminous lignite, like that of Brora. But in beds of a blue clay, intercalated with the sandstone, we find fossils in abundance, of a character less obscure. We spent a full half-hour in picking out shells from the bottom of a long dock-like hollow among the rocks, in which a bed of clay has yielded to the waves, while the strata on either side stand up over it like low wharfs on the opposite side of a river. The shells, though exceedingly fragile,—for they partake of the nature of the clayey matrix in which they are imbedded,—rise as entire as when they had died among the mud, years, mayhap ages, ere the sandstone had been deposited over them; and we were enabled at once to detect their extreme dissimilarity, as a group, to the shells of the Liasic deposit we had so lately quitted. We did not find in this bed a single Ammonite, Belemnite, or Nautilus; but chalky Bivalves, resembling our existing Tellina, in vast abundance,mixed with what seem to be a small Buccinum and a minute Trochus, with numerous rather equivocal fragments of a shell resembling an Oiliva. So thickly do they lie clustered together in this deposit, that in some patches where the sad-colored argillaceous ground is washed bare by the sea, it seems marbled with them into a light gray tint. The group more nearly resembles in type a recent one than any I have yet seen in a secondary deposit, except perhaps in the Weald of Moray, where we find in one of the layers a Planorbis scarce distinguishable from those of our ponds and ditches, mingled with a Paludina that seems as nearly modelled after the existing form. From the absence of the more characteristic shells of the Oölite, I am inclined to deem the deposit one of estuary origin. Its clays were probably thrown down, like the silts of so many of our rivers, in some shallow bay, where the waters of a descending stream mingled with those of the sea, and where, though shells nearly akin to our existing periwinkles and whelks congregate thickly, the Belemnite, seared by the brackish water, never plied its semi-cartilaginous fins, or the Nautilus or Ammonite hoisted its membranaceous sail.
We pass on towards the north. A thick bed of an extremely soft white sandstone presents here, for nearly half a mile together, its front to the waves, and exhibits, under the incessant wear of the surf, many singularly grotesque combinations of form. The low precipices, undermined at the base, beetle over like the sides of stranded vessels. One of the projecting promontories we find hollowed through and through by a tall rugged archway; while the outer pier of the arch,—if pier we may term it,—worn to a skeleton, and jutting outwards with a knee-like angle, presents the appearance of a thin ungainly leg and splay foot, advanced, as if in awkward courtesy, to the breakers.But in a winter or two, judging from its present degree of attenuation, and the yielding nature of its material, which resembles a damaged mass of arrow-root, consolidated by lying in the leaky hold of a vessel, its persevering courtesies will be over, and pier and archway must lie in shapeless fragments on the beach. Wherever the surf has broken into the upper surface of this sandstone bed, and worn it down to nearly the level of the shore, what seem a number of double ramparts, fronting each other, and separated by deep square ditches exactly parallel in the sides, traverse the irregular level in every direction. The ditches vary in width from one to twelve feet; and the ramparts, rising from three to six feet over them, are perpendicular as the walls of houses, where they front each other, and descend on the opposite sides in irregular slopes. The iron block, with square groove and projecting ears, that receives the bar of a railway, and connects it with the stone below, represents not inadequately a section of one of these ditches, with its ramparts. They form here the sole remains of dykes of an earthy trap, which, though at one time in a state of such high fusion that they converted the portions of soft sandstone in immediate contact with them into the consistence of quartz rock, have long since mouldered away, leaving but the hollow rectilinear rents which they had occupied, surmounted by the indurated walls which they had baked. Some of the most curious appearances, however, connected with the sandstone, though they occur chiefly in an upper bed, are exhibited by what seem fields of petrified mushrooms, of a gigantic size, that spread out in some places for hundreds of yards under the high-water level. These apparent mushrooms stand on thick squat stems, from a foot to eighteen inches in height; the heads are round like those of toad-stools, and vary from one foot to nearly two yards in diameter. In some specimens wefind two heads joined together in a form resembling a squat figure ofeight, of what printers term the Egyptian type, or, to borrow the illustration of M'Culloch, "like the ancient military projectile known by the name of double-headed shot;" in other specimens three heads have coalesced in a trefoil shape, or rather in a shape like that of an ace of clubs divested of the stem. By much the greater number, however, are spherical. They are composed of concretionary masses, consolidated, like the walls of the dykes, though under some different process, into a hard siliceous stone, that has resisted those disintegrating influences of the weather and the surf, under which the yielding matrix in which they were embedded has worn from around them. Here and there we find them lying detached on the beach, like huge shot, compared with which the greenstone balls of Mons Meg are but marbles for children to play with; in other cases they project from the mural front of rampart-like precipices, as if they had been showered into them by the ordnance of some besieging battery, and had stuck fast in the mason-work. Abbotsford has been described as a romance in stone and lime; we have here, on the shores of Laig, what seems a wild but agreeable tale, of the extravagant cast of "Christabel," or the "Rhyme of the Ancient Mariner," fretted into sandstone. But by far the most curious part of the story remains to be told.
The hollows and fissures of the lower sandstone bed we find filled with a fine quartzose sand, which, from its pure white color, and the clearness with which the minute particles reflect the light, reminds one of accumulations of potato-flour drying in the sun. It is formed almost entirely of disintegrated particles of the soft sandstone; and as we at first find it occurring in mere handfuls, that seem as if they had been detached from the mass during the last fewtides, we begin to marvel to what quarter the missing materials of the many hundred cubic yards of rock, ground down along the shore in this bed during the last century or two, have been conveyed away. As we pass on northwards, however, we see the white sand occurring in much larger quantities,—here heaped up in little bent-covered hillocks above the reach of the tide,—there stretching out in level, ripple-marked wastes into the waves,—yonder rising in flat narrow spits among the shallows. At length we reach a small, irregularly-formed bay, a few hundred feet across, floored with it from side to side; and see it, on the one hand, descending deep into the sea, that exhibits over its whiteness a lighter tint of green, and, on the other, encroaching on the land, in the form of drifted banks, covered with the plants common to our tracts of sandy downs. The sandstone bed that has been worn down to form it contains no fossils, save here and there a carbonaceous stem; but in an underlying harder stratum we occasionally find a few shells; and, with a specimen in my hand charged with a group of bivalves resembling the existing conchifera of our sandy beaches, I was turning aside this sand of the Oölite, so curiously reduced to its original state, and marking how nearly the recent shells that lay embedded in it resembled the extinct ones that had lain in it so long before, when I became aware of a peculiar sound that it yielded to the tread, as my companions paced over it. I struck it obliquely with my foot, where the surface lay dry and incoherent in the sun, and the sound elicited was a shrill, sonorous note, somewhat resembling that produced by a waxed thread, when tightened between the teeth and the hand, and tipped by the nail of the forefinger. I walked over it, striking it obliquely at each step, and with every blow the shrill note was repeated. My companions joined me; and we performed a concert, in which, if we couldboast of but little variety in the tones produced, we might at least challenge all Europe for an instrument of the kind which produced them. It seemed less wonderful that there should be music in the granite of Memnon, than in the loose Oölitic sand of the Bay of Laig. As we marched over the drier tracts, an incessantwoo,woo,woo, rose from the surface, that might be heard in the calm some twenty or thirty yards away; and we found that where a damp semi-coherent stratum lay at the depth of three or four inches beneath, and all was dry and incoherent above, the tones were loudest and sharpest, and most easily evoked by the foot. Our discovery,—for I trust I may regard it as such,—adds a third locality to two previously known ones, in which what may be termed the musical sand,—no unmeet counterpart to the "singing water" of the tale,—has now been found. And as the island of Eigg is considerably more accessible thanJabel Nakous, in Arabia Petræa, orReg-Rawan, in the neighborhood of Cabul, there must be facilities presented through the discovery which did not exist hitherto, for examining the phenomenon in acoustics which it exhibits,—a phenomenon, it may be added, which some of our greatest masters of the science have confessed their inability to explain.
Jabel Nakous, or the "Mountain of the Bell," is situated about three miles from the shores of the Gulf of Suez, in that land of wonders which witnessed for forty years the journeyings of the Israelites, and in which the granite peaks of Sinai and Horeb overlook an arid wilderness of rock and sand. It had been known for many ages by the wild Arab of the desert, that there rose at times from this hill a strange, inexplicable music. As he leads his camel past in the heat of the day, a sound like the first low tones of an Æolian harp stirs the hot breezeless air. It swells louder and louder in progressive undulations, till at lengththe dry baked earth seems to vibrate under foot, and the startled animal snorts and rears, and struggles to break away. According to the Arabian account of the phenomenon, says Sir David Brewster, in his "Letters on Natural Magic," there is a convent miraculously preserved in the bowels of the hill; and the sounds are said to be those of the "Nakous, a long metallic ruler, suspended horizontally, which the priest strikes with a hammer, for the purpose of assembling the monks to prayer." There exists a tradition that on one occasion a wandering Greek saw the mountain open, and that, entering by the gap, he descended into the subterranean convent, where he found beautiful gardens and fountains of delicious water, and brought with him to the upper world, on his return, fragments of consecrated bread. The first European traveller who visitedJabel Nakous, says Sir David, was M. Seetzen, a German. He journeyed for several hours over arid sands, and under ranges of precipices inscribed by mysterious characters, that tell, haply, of the wanderings of Israel under Moses. And reaching, about noon, the base of the musical fountain, he found it composed of a white friable sandstone, and presenting on two of its sides sandy declivities. He watched beside it for an hour and a quarter, and then heard, for the first time, a low undulating sound, somewhat resembling that of a humming top, which rose and fell, and ceased and began, and then ceased again; and in an hour and three quarters after, when in the act of climbing along the declivity, he heard the sound yet louder and more prolonged. It seemed as if issuing from under his knees, beneath which the sand, disturbed by his efforts, was sliding downwards along the surface of the rock. Concluding that the sliding sand was the cause of the sounds, not an effect of the vibrations which they occasioned, he climbed to the top of one of the declivities, and, sliding downwards, exerted himselfwith hands and feet to set the sand in motion. The effect produced far exceeded his expectations; the incoherent sand rolled under and around in a vast sheet; and so loud was the noise produced, that "the earth seemed to tremble beneath him to such a degree, that he states he should certainly have been afraid if he had been ignorant of the cause." At the time Sir David Brewster wrote (1832), the only other European who had visitedJabel Nakouswas Mr. Gray, of University College, Oxford. This gentleman describes the noises he heard, but which he was unable to trace to their producing cause, as "beginning with a low continuous murmuring sound, which seemed to rise beneath his feet," but "which gradually changed into pulsations as it became louder, so as to resemble the striking of a clock, and became so strong at the end of five minutesas to detach the sand." The Mountain of the Bell has been since carefully explored by Lieutenant J. Welsted, of the Indian navy; and the reader may see it exhibited in a fine lithograph, in his travels, as a vast irregularly conical mass of broken stone, somewhat resembling one of our Highland cairns, though, of course, on a scale immensely more huge, with a steep, angular slope of sand resting in a hollow in one of its sides, and rising to nearly its apex. "It forms," says Lieutenant Welsted, "one of a ridge of low, calcareous hills, at a distance of three and a half miles from the beach, to which a sandy plain, extending with a gentle rise to their base, connects them. Its height, about four hundred feet, as well as the material of which it is composed,—a light-colored friable sandstone,—is about the same as the rest of the chain; but an inclined plane of almost impalpable sand rises at an angle of forty degrees with the horizon, and is bounded by a semi-circle of rocks, presenting broken, abrupt, and pinnacled forms, and extending to the base of this remarkable hill. Although their shape and arrangementin some respects may be said to resemble a whispering gallery, yet I determined by experiment that their irregular surface renders them but ill adapted for the production of an echo. Seated at a rock at the base of the sloping eminence, I directed one of the Bedouins to ascend; and it was not until he had reached some distance that I perceived the sand in motion, rolling down the hill to the depth of a foot. It did not, however, descend in one continued stream; but, as the Arab scrambled up, it spread out laterally and upwards, until a considerable portion of the surface was in motion. At their commencement the sounds might be compared to the faint strains of an Æolian harp when its strings first catch the breeze: as the sand became more violently agitated by the increased velocity of the descent, the noise more nearly resembled that produced by drawing the moistened fingers over glass. As it reached the base, the reverberations attained the loudness of distant thunder, causing the rock on which we were seated to vibrate; and our camels,—animals not easily frightened,—became so alarmed that it was with difficulty their drivers could restrain them."
"The hill ofReg-Rawanor the 'Moving Sand,'" says the late Sir Alexander Burnes, by whom the place was visited in the autumn of 1837, and who has recorded his visit in a brief paper, illustrated by a rude lithographic view, in the "Journal of the Asiatic Society" for 1838, "is about forty miles north of Cabul, towards Hindu-kush, and near the base of the mountains." It rises to the height of about four hundred feet, in an angle formed by the junction of two ridges of hills; and a sheet of sand, "pure as that of the sea-shore," and which slopes in an angle of forty degrees, reclines against it from base to summit. As represented in the lithograph, there projects over the steep sandy slope on each side, as in the "Mountain of the Bell," still steeperbarriers of rock; and we are told by Sir Alexander, that though "the mountains here are generally composed of granite or mica, atReg-Rawanthere is sandstone and lime." The situation of the sand is curious, he adds: it is seen from a great distance; and as there is none other in the neighborhood, "it might almost be imagined, from its appearance, that the hill had been cut in two, and that the sand had gushed forth as from a sand-bag." "When set in motion by a body of people who slide down it, a sound is emitted. On the first trial we distinctly heard two loud hollow sounds, such as would be given by a large drum;"—"there is an echo in the place; and the inhabitants have a belief that the sounds are only heard on Friday, when the saint ofReg-Rawan, who is interred hard by, permits." The phenomenon, like the resembling one in Arabia, seems to have attracted attention among the inhabitants of the country at an early period; and the notice of an eastern annalist, the Emperor Baber, who flourished late in the fifteenth century, and, like Cæsar, conquered and recorded his conquests, still survives. He describes it as theKhwaja Reg-Rawan, "a small hill, in which there is a line of sandy ground reaching from the top to the bottom," from which there "issues in the summer season the sound of drums and nagarets." In connection with the fact that the musical sand of Eigg is composed of a disintegrated sandstone of the Oölite, it is not quite unworthy of notice that sandstone and lime enter into the composition of the hill ofReg-Rawan,—that the district in which the hill is situated is not a sandy one,—and that its slope of sonorous sand seems as if it had issued from its side. These various circumstances, taken together, lead to the inference that the sand may have originated in the decomposition of the rock beneath. It is further noticeable, that theJabel Nakousis composed of a white friable sandstone, resembling that of the white friablebed of the Bay of Laig, and that it belongs to nearly the same geological era. I owe to the kindness of Dr. Wilson of Bombay, two specimens which he picked up in Arabia Petræa, of spines of Cidarites of the mace-formed type so common in the Chalk and Oölite, but so rare in the older formations. Dr. Wilson informs me that they are of frequent occurrence in the desert of Arabia Petræa, where they are termed by the Arabs petrified olives; that nummulites are also abundant in the district; and that the various secondary rocks he examined in his route through it seem to belong to the Cretaceous group. It appears not improbable, therefore, that all the sonorous sand in the world yet discovered is formed, like that of Eigg, of disintegrated sandstone; and at least two-thirds of it of the disintegrated sandstone of secondary formations, newer than the Lias. But how it should be at all sonorous, whatever its age or origin, seems yet to be discovered. There are few substances that appear worse suited than sand to communicate to the atmosphere those vibratory undulations that are the producing causes of sound: the grains, even when sonorous individually, seem, from their inevitable contact with each other, to exist under the influence of that simple law in acoustics which arrests the tones of the ringing glass or struck bell, immediately as they are but touched by some foreign body, such as the hand or finger. The one grain, ever in contact with several other grains, is a glass or bell on which the hand always rests. And the difficulty has been felt and acknowledged. Sir John Herschel, in referring to the phenomenon of theJabel Nakous, in his "Treatise on Sound," in the "Encyclopædia Metropolitana," describes it as to him "utterly inexplicable;" and Sir David Brewster, whom I had the pleasure of meeting in December last, assured me it was not less a puzzle to him than to Sir John. An eastern traveller, who attributes itsproduction to "a reduplication of impulse setting air in vibration in a focus of echo," means, I suppose, saying nearly the same thing as the two philosophers, and merely conveys his meaning in a less simple style.
I have not yet procured what I expect to procure soon,—sand enough from the musical bay at Laig to enable me to make its sonorous qualities the subject of experiment at home. It seems doubtful whether a small quantity set in motion on an artificial slope will serve to evolve the phenomena which have rendered the Mountain of the Bell so famous. Lieutenant Welsted informs us, that when his Bedouin first set the sand in motion, there was scarce any perceptible sound heard;—it was rolling downwards for many yards around him to the depth of a foot, ere the music arose; and it is questionable whether the effect could be elicited with some fifty or sixty pounds weight of the sand of Eigg, on a slope of but at most a few feet, which it took many hundred weight of sand ofJabel Nakous, and a slope of many yards, to produce. But in the stillness of a close room, it is just possible that it may. I have, however, little doubt, that from small quantities the sound evoked by the foot on the shore may be reproduced: enough will lie within the reach of experiment to demonstrate the strange difference which exists between this sonorous sand of the Oölite, and the common unsonorous sand of our sea-beaches; and it is certainly worth while examining into the nature and producing causes of a phenomenon so curious in itself, and which has been characterized by one of the most distinguished of living philosophers as "the most celebrated of all the acoustic wonders which the natural world presents to us." In the forthcoming number of the "North British Review,"—which appears on Monday first,[1]—the reader will find the sonorous sand of Eigg referred to, in anarticle the authorship of which will scarcely be mistaken. "We have here," says the writer, after first describing the sounds ofJabel Nakous, and then referring to those of Eigg, "the phenomenon in its simple state, disembarrassed from reflecting rocks, from a hard bed beneath, and from cracks and cavities that might be supposed to admit the sand; and indicating as its cause, either the accumulated vibration of the air when struck by the driven sand, or the accumulated sounds occasioned by the mutual impact of the particles of sand against each other. If a musket-ball passing through the air emits a whistling note, each individual particle of sand must do the same, however faint be the note which it yields; and the accumulation of these infinitesimal vibrations must constitute an audible sound, varying with the number and velocity of moving particles. In like manner, if two plates of silex or quartz, which are but large crystals of sand, give out a musical sound when mutually struck, the impact or collision of two minute crystals or particles of sand must do the same, in however inferior a degree; and the union of all these sounds, though singly imperceptible, may constitute the musical notes of the Bell Mountain, or the lesser sounds of the trodden sea-beach at Eigg."
Here is a vigorous effort made to unlock the difficulty. I should, however, have mentioned to the philosophic writer,—what I inadvertently failed to do,—that the sounds elicited from the sand of Eigg seem as directly evoked by the slant blow dealt it by the foot, as the sounds similarly evoked from a highly waxed floor, or a board strewed over with ground rosin. The sharp shrill note follows the stroke, altogether independently of the grains driven into the air. My omission may serve to show how much safer it is for those minds of the observant order, that serve as hands and eyes to the reflective ones, to prefer incurring the risk ofbeing even tediously minute in their descriptions, to the danger of being inadequately brief in them. But, alas! for purposes of exact science, rarely are verbal descriptions otherwise than inadequate. Let us look, for example, at the various accounts given us ofJabel Nakous. There are strange sounds heard proceeding from a hill in Arabia, and various travellers set themselves to describe them. The tones are those of the conventNakous, says the wild Arab;—there must be a convent buried under the hill. More like the sounds of a humming-top, remarks a phlegmatic German traveller. Not quite like them, says an English one in an Oxford gown;—they resemble rather the striking of a clock. Nay, listen just a little longer and more carefully, says a second Englishman, with epaulettes on his shoulder: "the sounds at their commencement may be compared to the faint strains of an Æolian harp when its strings first catch the breeze," but anon, as the agitation of the sand increases, they "more nearly resemble those produced by drawing the moistened fingers over glass." Not at all, exclaims the warlike Zahor Ed-din Muhammed Baber, twirling his whiskers: "I know a similar hill in the country towards Hindu-kush: it is the sound of drums and nagarets that issues from the sand." All we really know of this often-described music of the desert, after reading all the descriptions, is, that its tones bear certain analogies to certain other tones,—analogies that seem stronger in one direction to one ear, and stronger in another direction to an ear differently constituted, but which do not exactly resemble any other sounds in nature. The strange music ofJabel Nakous, as a combination of tones, is essentially unique.
Trap-Dykes—"Cotton Apples"—Alternation of Lacustrine with Marine Remains—Analogy from the Beds of Esk—Aspect of the Island on its narrow Front—The Puffin—Ru-Stoir—Development of Old Red Sandstone—Striking Columnar character of Ru-Stoir—Discovery of Reptilian Remains—John Stewart's wonder at the Bones in the Stones—Description of the Bones—"Dragons, Gorgons, and Chimeras"—Exploration and Discovery pursued—The Midway Shieling—A Celtic Welcome—Return of the Yacht—"Array of Fossils new to Scotch Geology"—A Geologist's Toast—Hoffman and his Fossil.
Trap-Dykes—"Cotton Apples"—Alternation of Lacustrine with Marine Remains—Analogy from the Beds of Esk—Aspect of the Island on its narrow Front—The Puffin—Ru-Stoir—Development of Old Red Sandstone—Striking Columnar character of Ru-Stoir—Discovery of Reptilian Remains—John Stewart's wonder at the Bones in the Stones—Description of the Bones—"Dragons, Gorgons, and Chimeras"—Exploration and Discovery pursued—The Midway Shieling—A Celtic Welcome—Return of the Yacht—"Array of Fossils new to Scotch Geology"—A Geologist's Toast—Hoffman and his Fossil.
Weleave behind us the musical sand, and reach the point of the promontory which forms the northern extremity of the Bay of Laig. Wherever the beach has been swept bare, we see it floored with trap-dykes worn down to the level, but in most places accumulations of huge blocks of various composition cover it up, concealing the nature of the rock beneath. The long semi-circular wall of precipice which, sweeping inwards at the bottom of the bay, leaves to the inhabitants between its base and the beach their fertile meniscus of land, here abuts upon the coast. We see its dark forehead many hundred feet overhead, and the grassy platform beneath, now narrowed to a mere talus, sweeping upwards to its base from the shore,—steep, broken, lined thick with horizontal pathways, mottled over with ponderous masses of rock.
Among the blocks that load the beach, and render our onward progress difficult and laborious, we detect occasional fragments of an amygdaloidal basalt, charged with a white zeolite, consisting of crystals so extremely slender that the balls, with their light fibrous contents, remind us of cottonapples divested of the seeds. There occur, though more rarely, masses of a hard white sandstone, abounding in vegetable impressions, which, from their sculptured markings, recalled to memory the Sigillaria of the Coal Measures. Here and there, too, we find fragments of a calcareous stone, so largely charged with compressed shells, chiefly bivalves, that it may be regarded as a shell breccia. There occur, besides, slabs of fibrous limestone, exactly resembling the limestone of the ichthyolite beds of the Lower Old Red; and blocks of a hard gray stone, of silky lustre in the fresh fracture, thickly speckled with carbonaceous markings. These fragmentary masses,—all of them, at least, except the fibrous limestone, which occurs in mere plank-like bands,—represent distinct beds, of which this part of the island is composed, and which present their edges, like courses of ashlar in a building, in the splendid section that stretches from the tall brow of the precipice to the beach; though in the slopes of the talus, where the lower beds appear in but occasional protrusions and land-slips, we find some difficulty in tracing their order of succession.
Near the base of the slope, where the soil has been undermined and the rock laid bare by the waves, there occur beds of a bituminous black shale,—resembling the dark shales so common in the Coal Measures,—that seem to be of fresh water or estuary origin. Their fossils, though numerous, are ill preserved; but we detect in them scales and plates of fishes, at least two species of minute bivalves, one of which very much resembles a Cyclas; and in some of the fragments, shells of Cypris lie embedded in considerable abundance. After all that has been said and written by way of accounting for those alternations of lacustrine with marine remains, which are of such frequent occurrence in the various formations, secondary and tertiary, from the Coal Measures downwards, it does seem strange enoughthat the estuary, or fresh-water lake, should so often in the old geologic periods have changed places with the sea. It is comparatively easy to conceive that the inner Hebrides should have once existed as a broad ocean sound, bounded on one or either side by Oölitic islands, from which streams descended, sweeping with them, to the marine depths, productions, animal and vegetable, of the land. But it is less easy to conceive, that in that sound, the area covered by the ocean one year should have been covered by a fresh-water lake in perhaps the next, and then by the ocean again a few years after. And yet among the Oölitic deposits of the Hebrides evidence seems to exist that changes of this nature actually took place. I am not inclined to found much on the apparently fresh-water character of the bituminous shales of Eigg;—the embedded fossils are all too obscure to be admitted in evidence; but there can exist no doubt that fresh water, or at least estuary formations, do occur among the marine Oölites of the Hebrides. Sir R. Murchison, one of the most cautious, as he is certainly one of the most distinguished, of living geologists, found in a northern district of Skye, in 1826, a deposit containing Cyclas, Paludina, Neritina,—all shells of unequivocally fresh-water origin,—which must have been formed, he concludes, in either a lake or estuary. What had been sea at one period had been estuary or lake at another. In every case, however, in which these intercalated deposits are restricted to single strata of no great thickness, it is perhaps safer to refer their formation to the agency of temporary land-floods, than to that of violent changes of level, now elevating and now depressing the surface. There occur, for instance, among the marine Oölites of Brora,—the discovery of Mr. Robertson, of Inverugie,—two strata containing fresh-water fossils in abundance; but the one stratum is little more than an inch in thickness,—the otherlittle more than a foot; and it seems considerably more probable, that such deposits should have owed their existence to extraordinary land-floods, like those which in 1829 devastated the province of Moray, and covered over whole miles of marine beach with the spoils of land and river, than that a sea-bottom should have been elevated for their production, into a fresh-water lake, and then let down into a sea-bottom again. We find it recorded in the "Shepherd's Calendar," that after the thaw which followed the great snow-storm of 1794, there were found on a part of the sands of the Solway Frith known as the Beds of Esk, where the tide disgorges much of what is thrown into it by the rivers, "one thousand eight hundred and forty sheep, nine black cattle, three horses, two men, one woman, forty-five dogs, and one hundred and eighty hares, beside a number of meaner animals." A similar storm in an earlier time, with a soft sea-bottom prepared to receive and retain its spoils, would have formed a fresh-water stratum intercalated in a marine deposit.
Rounding the promontory, we lose sight of the Bay of Laig, and find the narrow front of the island that now presents itself exhibiting the appearance of a huge bastion. The green talus slopes upwards, as its basement, for full three hundred feet; and a noble wall of perpendicular rock, that towers over and beyond for at least four hundred feet more, forms the rampart. Save towards the sea, the view is of but limited extent; we see it restricted, on the landward side, to the bold face of the bastion; and in a narrow and broken dell that runs nearly parallel to the shore for a few hundred yards between the top of the talus and the base of the rampart,—a true covered way,—we see but the rampart alone. But the dizzy front of black basalt, dark as night, save where a broad belt of light-colored sandstone traverses it in an angular direction, like a whitesash thrown across a funeral robe,—the fantastic peaks and turrets in which the rock terminates atop,—the masses of broken ruins, roughened with moss and lichen, that have fallen from above, and lie scattered at its base,—the extreme loneliness of the place, for we have left behind us every trace of the human family,—and the expanse of solitary sea which it commands,—all conspire to render the scene a profoundly imposing one. It is one of those scenes in which a man feels that he is little, and that nature is great. There is no precipice in the island in which the puffin so delights to build as among the dark pinnacles overhead, or around which the silence is so frequently broken by the harsh scream of the eagle. The sun had got far adown the sky ere we had reached the covered way at the base of the rock. All lay dark below; and the red light atop, half absorbed by the dingy hues of the stone, shone with a gleam so faint and melancholy, that it served but to deepen the effect of the shadows.
The puffin, a comparatively rare bird in the inner Hebrides, builds, I was told, in great numbers in the continuous line of precipice which, after sweeping for a full mile round the Bay of Laig, forms the pinnacled rampart here, and then, turning another angle of the island, runs on parallel to the coast for about six miles more. In former times the puffin furnished the islanders, as in St. Kilda, with a staple article of food, in those hungry months of summer in which the stores of the old crop had begun to fail, and the new crop had not yet ripened; and the people of Eigg, taught by their necessities, were bold cragsmen. But men do not peril life and limb for the mere sake of a meal, save when they cannot help it; and the introduction of the potato has done much to put out the practice of climbing for the bird, except among a few young lads, who find excitement enough in the work to pursue it for its own sake, as anamusement. I found among the islanders what was said to be a piece of the natural history of the puffin, sufficiently apocryphal to remind one of the famous passage in the history of the barnacle, which traced the lineage of the bird to one of the pedunculated cirripedes, and the lineage of the cirripede to a log of wood. The puffin feeds its young, say the islanders, on an oily scum of the sea, which renders it such an unwieldy mass of fat, that about the time when it should be beginning to fly, it becomes unable to get out of its hole. The parent bird, not in the least puzzled, however, treats the case medicinally, and,—like mothers of another two-legged genus, who, when their daughters get over stout, put them through a course of reducing acids to bring them down,—feeds it on sorrel leaves for several days together, till, like a boxer under training, it gets thinned to the proper weight, and becomes able, not only to get out of its cell, but also to employ its wings.
We pass through the hollow, and, reaching the farther edge of the bastion, towards the east, see a new range of prospect opening before us. There is first a long unbroken wall of precipice,—a continuation of the tall rampart overhead,—relieved along its irregular upper line by the blue sky. We mark the talus widening at its base, and expanding, as on the shores of the Bay of Laig, into an irregular grassy platform, that, sinking midway into a ditch-like hollow, rises again towards the sea, and presents to the waves a perpendicular precipice of redstone. The sinking sun shone brightly this evening; and the warm hues of the precipice, which bears the name ofRu-Stoir,—the Red Head,—strikingly contrasted with the pale and dark tints of the alternating basalts and sandstones in the taller cliff behind. The ditch-like hollow, which seems to indicate the line of a fault, cuts off this red headland from all the other rocks of the island, from which it appears to differ as considerablyin texture as in hue. It consists mainly of thick beds of a pale red stone, which M'Culloch regarded as a trap, and which, intercalated with here and there a thin band of shale, and presenting not a few of the mineralogical appearances of what geologists of the school of the late Mr. Cunningham term Primary Old Red Sandstone, in some cases has been laid down as a deposit of Old Red proper, abutting in the line of a fault on the neighboring Oölites and basalts. In the geological map which I carried with me,—not one of high authority however,—I found it actually colored as a patch of this ancient system. The Old Red Sandstone is largely developed in the neighboring island of Rum, in the line of which theRu-Stoirseems to have a more direct bearing than any of the other deposits of Eigg; and yet the conclusion regarding this red headland merely adds one proof more to the many furnished already, of the inadequacy of mineralogical testimony, when taken in evidence regarding the eras of the geologist. The hard red beds ofRu-Stoirbelong, as I was fortunate enough this evening to ascertain, not to the ages of the Coccosteus and Pterichthys, but to the far later ages of the Plesiosaurus and the fossil crocodile. I found them associated with more reptilian remains, of a character more unequivocal than have been yet exhibited by any other deposit in Scotland.
What first strikes the eye, in approaching theRu-Stoirfrom the west, is the columnar character of the stone. The precipices rise immediately over the sea, in rude colonnades of from thirty to fifty feet in height; single pillars, that have fallen from their places in the line, and exhibit a tenacity rare among the trap-rocks,—for they occur in unbroken lengths of from ten to twelve feet,—lie scattered below; and in several places where the waves have joined issue with the precipices in the line on which thebase of the columns rest, and swept away the supporting foundation, the colonnades open into roomy caverns, that resound to the dash of the sea. Wherever the spray lashes, the pale red hue of the stone prevails, and the angles of the polygonal shafts are rounded; while higher up all is sharp-edged, and the unweathered surface is covered by a gray coat of lichens. The tenacity of the prostrate columns first drew my attention. The builder scant of materials would have experienced no difficulty in finding among them sufficient lintels for apertures from eight to twelve feet in width. I was next struck with the peculiar composition of the stone; it much rather resembles an altered sandstone, in at least the weathered specimens, than a trap, and yet there seemed nothing to indicate that it was anOld RedSandstone. Its columnar structure bore evidence to the action of great heat; and its pale red color was exactly that which the Oölitic sandstones of the island, with their slight ochreous tinge, would assume in a common fire. And so I set myself to look for fossils. In the columnar stone itself I expected none, as none occur in vast beds of the unaltered sandstones, out of some one of which I supposed it might possibly have been formed; and none I found: but in a rolled block of altered shale of a much deeper red than the general mass, and much more resembling Old Red Sandstone, I succeeded in detecting several shells, identical with those of the deposit of blue clay described in a former chapter. There occurred in it the small univalve resembling a Trochus, together with the oblong bivalve, somewhat like a Tellina; and, spread thickly throughout the block, lay fragments of coprolitic matter, and the scales and teeth of fishes. Night was coming on, and the tide had risen on the beach; but I hammered lustily, and laid open in the dark red shale a vertebral joint, a rib, and a parallelogramical fragment of solid bone, noneof which could have belonged to any fish. It was an interesting moment for the curtain to drop over the promontory ofRu-Stoir; I had thus already found in connection with it well nigh as many reptilian remains as had been found in all Scotland before,—for there could exist no doubt that the bones I laid open were such; and still more interesting discoveries promised to await the coming morning, and a less hasty survey. We found a hospitable meal awaiting us at a picturesque old two-story house, with, what is rare in the island, a clump of trees beside it, which rises on the northern angle of the Oölitic meniscus; and after our day's hard work in the fresh sea-air, we did ample justice to the viands. Dark night had long set in ere we reached our vessel.
Next day was Saturday; and it behooved my friend, the minister,—as scrupulously careful in his pulpit preparations for the islanders of Eigg as if his congregation were an Edinburgh one,—to remain on board, and study his discourse for the morrow. I found, however, no unmeet companion for my excursion in his trusty mate John Stewart. John had not very much English, and I had no Gaelic; but we contrived to understand one another wonderfully well; and ere evening I had taught him to be quite as expert in hunting dead crocodiles as myself. We reached theRu-Stoir, and set hard to work with hammer and chisel. The fragments of red shale were strewed thickly along the shore for at least three quarters of a mile; wherever the red columnar rock appeared, there lay the shale, in water-worn blocks, more or less indurated; but the beach was covered over with shingle and detached masses of rock, and we could nowhere find itin situ. A winter storm powerful enough to wash the beach bare might do much to assist the explorer. There is a piece of shore on the eastern coast of Scotland, on which for yearstogether I used to pick up nodular masses of lime containing fish of the Old Red Sandstone; but nowhere in the neighborhood could I find the ichthyolite bed in which they had originally formed. The storm of a single night swept the beach; and in the morning the ichthyolites lay revealedin situunder a stratum of shingle which I had a hundred times examined, but which, though scarce a foot in thickness, had concealed from me the ichthyolite bed for five twelvemonths together!
Wherever the altered shale ofRu-Stoirhas been thrown high on the beach, and exposed to the influences of the weather, we find it fretted over with minute organisms, mostly the scales, plates, bones, and teeth of fishes. The organisms, as is frequently the case, seem indestructible, while the hard matrix in which they are embedded has weathered from around them. Some of the scales present the rhomboidal outline, and closely resemble those of theLepidotus Minorof the Weald; others approximate in shape to an isosceles triangle. The teeth are of various forms: some of them, evidently palatal, are mere blunted protuberances glittering with enamel,—some of them present the usual slim, thorn-like type common in the teeth of the existing fish of our coasts,—some again are squat and angular, and rest on rectilinear bases, prolonged considerably on each side of the body of the tooth, like the rim of a hat or the flat head of a scupper nail. Of the occipital plates, some present a smooth enamelled surface, while some are thickly tuberculated,—each tubercle bearing a minute depression in its apex, like a crater on the summit of a rounded hill. We find reptilian bones in abundance,—a thing new to Scotch geology,—and in a state of keeping peculiarly fine. They not a little puzzled John Stewart: he could not resist the evidence of his senses: they were bones, he said, real bones,—there could be no doubt of that:therewere the joints ofa backbone, with the hole the brain-marrow had passed through; andtherewere shank-bones and ribs, and fishes' teeth; but how, he wondered, had they all got into the very heart of the hard red stones? He had seen what was called wood, he said, dug out of the side of the Scuir, without being quite certain whether it was wood or no; but there could be no uncertainty here. I laid open numerous vertebræ of various forms,—some with long spinous processes rising over the body orcentrumof the bone,—which I found in every instance, unlike that of the Ichthyosaurus, only moderately concave on the articulating faces; in others the spinous process seemed altogether wanting. Only two of the number bore any mark of the suture which unites, in most reptiles, the annular process to the centrum; in the others both centrum and process seemed anchylosed, as in quadrupeds, into one bone; and there remained no scar to show that the suture had ever existed. In some specimens the ribs seem to have been articulated to the sides of the centrum; in others there is a transverse process, but no marks of articulation. Some of the vertebræ are evidently dorsal, some cervical, one apparently caudal; and almost all agree in showing in front two little eyelets, to which the great descending artery seems to have sent out blood-vessels in pairs. The more entire ribs I was lucky enough to disinter have, as in those of crocodileans, double heads; and a part of a fibula, about four inches in length, seems also to belong to this ancient family. A large proportion of the other bones are evidently Plesiosaurian. I found the head of the flat humerus so characteristic of the extinct order to which the Plesiosaurus has been assigned, and two digital bones of the paddle, that, from their comparatively slender and slightly curved form, so unlike the digitals of its cogener the Ichthyosaurus, could have belonged evidently to no other reptile. I observed, too, in the slightly curved articulationsof not a few of the vertebræ, the gentle convexity in the concave centre, which, if not peculiar to the Plesiosaurus, is at least held to distinguish it from most of its contemporaries. Among the various nondescript organisms of the shale, I laid open a smooth angular bone, hollowed something like a grocer's scoop; a three-pronged caltrop-looking bone, that seems to have formed part of a pelvic arch; another angular bone, much massier than the first, regarding the probable position of which I could not form a conjecture, but which some of my geological friends deem cerebral; an extremely dense bone, imperfect at each end, which presents the appearance of a cylinder slightly flattened; and various curious fragments, which, with what our Scotch museums have not yet acquired,—entire reptilian fossils for the purposes of comparison,—might, I doubt not, be easily assigned to their proper places. It was in vain that, leaving John to collect the scattered pieces of shale in which the bones occurred, I set myself again and again to discover the bed from which they had been detached. The tide had fallen, and a range of skerries lay temptingly off, scarce a hundred yards from the water's edge: the shale beds might be among them, with Plesiosauri and crocodiles stretching entire; and fain would I have swum off to them, as I had done oftener than once elsewhere, with my hammer in my teeth, and with shirt and drawers in my hat; but a tall brown forest of kelp and tangle in which even a seal might drown, rose thick and perilous round both shore and skerries; a slight swell was felting the long fronds together; and I deemed it better, on the whole, that the discoveries I had already made should be recorded, than that they should be lost to geology, mayhap for a whole age, in the attempt to extend them.
The water, beautifully transparent, permitted the eye to penetrate into its green depths for many fathoms around,though every object presented, through the agitated surface, an uncertain and fluctuating outline. I could see, however, the pink-colored urchin warping himself up, by his many cables, along the steep rock-sides; the green crab stalking along the gravelly bottom; a scull of small rock-cod darting hither and thither among the tangle-roots; and a few large medusæ slowly flapping their continuous fins of gelatine in the opener spaces, a few inches under the surface. Many curious families had their representatives within the patch of sea which the eye commanded; but the strange creatures that had once inhabited it by thousands, and whose bones still lay sepulchred on its shores, had none. How strange, that the identical sea heaving around stack and skerry in this remote corner of the Hebrides should have once been thronged by reptile shapes more strange than poet ever imagined,—dragons, gorgons and chimeras! Perhaps of all the extinct reptiles, the Plesiosaurus was the most extraordinary. An English geologist has described it, grotesquely enough, and yet most happily, as a snakethreadedthrough a tortoise. And here on this very spot, must these monstrous dragons have disported and fed; here must they have raised their little reptile heads and long swan-like necks over the surface, to watch an antagonist or select a victim; here must they have warred and wedded, and pursued all the various instincts of their unknown natures. A strange story, surely, considering it is a true one! I may mention in the passing, that some of the fragments of the shale in which the remains are embedded have been baked by the intense heat into an exceedingly hard, dark-colored stone, somewhat resembling basalt. I must add further, that I by no means determine the rock with which we find it associated to be in reality an altered sandstone. Such is the appearance which it presents where weathered; but its general aspect is that of a porphyritictrap. Be it what it may, the fact is not at all affected, that the shores, wherever it occurs on this tract of insular coast, are strewed with reptilian remains of the Oölite.
The day passed pleasantly in the work of exploration and discovery; the sun had already declined far in the west; and, bearing with us our better fossils, we set out, on our return, by the opposite route to that along the Bay of Laig, which we had now thrice walked over. The grassy talus so often mentioned continues to run on the eastern side of the island for about six miles, between the sea and the inaccessible rampart of precipice behind. It varies in breadth from about two to four hundred yards; the rampart rises over it from three to five hundred feet; and a noble expanse of sea, closed in the distance by a still nobler curtain of blue hills, spreads away from its base: and it was along this grassy talus that our homeward road lay. Let the Edinburgh reader imagine the fine walk under Salisbury Crags lengthened some twenty times,—the line of precipices above heightened some five or six times,—the gravelly slope at the base not much increased in altitude, but developed transversely into a green undulating belt of hilly pasture, with here and there a sunny slope level enough for the plough, and here and there a rough wilderness of detached crags and broken banks; let him further imagine the sea sweeping around the base of this talus, with the nearest opposite land—bold, bare and undulating atop—some six or eight miles distant; and he will have no very inadequate idea of the peculiar and striking scenery through which, this evening, our homeward route lay. I have scarce ever walked over a more solitary tract. The sea shuts it in on the one hand, and the rampart of rocks on the other; there occurs along its entire length no other human dwelling than a lonely summer shieling; for full one-half the way we saw no trace of man; and the wildness of the few cattle whichwe occasionally startled in the hollows showed us that man was no very frequent visitor among them. About half an hour before sunset we reached the midway shieling.
Rarely have I seen a more interesting spot, or one that, from its utter loneliness, so impressed the imagination. The shieling, a rude low-roofed erection of turf and stone, with a door in the centre some five feet in height or so, but with no window, rose on the grassy slope immediately in front of the vast continuous rampart. A slim pillar of smoke ascends from the roof, in the calm, faint and blue within the shadow of the precipice, but it caught the sunlight in its ascent, and blushed, ere it melted into the ether, a ruddy brown. A streamlet came pouring from above in a long white thread, that maintained its continuity unbroken for at least two-thirds of the way; and then, untwisting into a shower of detached drops, that pattered loud and vehemently in a rocky recess, it again gathered itself up into a lively little stream, and, sweeping past the shieling, expanded in front into a circular pond, at which a few milch cows were leisurely slaking their thirst. The whole grassy talus, with a strip mayhap a hundred yards wide, of deep green sea, lay within the shadow of the tall rampart; but the red light fell, for many a mile beyond, on the glassy surface; and the distant Cuchullin Hills, so dark at other times, had all their prominent slopes and jutting precipices tipped with bronze; while here and there a mist streak, converted into bright flame, stretched along their peaks or rested on their sides. Save the lonely shieling, not a human dwelling was in sight. An island girl of eighteen, more than merely good-looking, though much embrowned by the sun, had come to the door to see who the unwonted visitors might be, and recognized in John Stewart an old acquaintance. John informed her in her own language that I was Mr. Swanson's sworn friend, and not aModerate, but one of their own people, and that Ihad fasted all day, and had come for a drink of milk. The name of her minister proved a strongly recommendatory one: I have not yet seen the true Celtic interjection of welcome,—the kindly "O o o,"—attempted on paper; but I had a very agreeable specimen of it on this occasion,viva voce. And as she set herself to prepare for us a rich bowl of mingled milk and cream, John and I entered the shieling. There was a turf fire at the one end, at which there sat two little girls, engaged in keeping up the blaze under a large pot, but sadly diverted from their work by our entrance; while the other end was occupied by a bed of dry straw, spread on the floor from wall to wall, and fenced off at the foot by a line of stones. The middle space was occupied by the utensils and produce of the dairy,—flat wooden vessels of milk, a butter-churn, and a tub half-filled with curd; while a few cheeses, soft from the press, lay on a shelf above. The little girls were but occasional visitors, who had come, out of a juvenile frolic, to pass the night in the place; but I was informed by John that the shieling had two other inmates, young women, like the one so hospitably engaged in our behalf, who were out at the milking, and that they lived here all alone for several months every year, when the pasturage was at its best, employed in making butter and cheese for their master, worthy Mr. M'Donald of Keill. They must often feel lonely when night has closed darkly over mountain and sea, or in those dreary days of mist and rain so common in the Hebrides, when nought may be seen save the few shapeless crags that stud the nearer hillocks around them, and nought heard save the moaning of the wind in the precipices above, or the measured dash of the wave on the wild beach below. And yet they would do ill to exchange their solitary life and rude shieling for the village dwellings and gregarious habits of the females who ply their rural labors in bands among therich fields of the Lowlands, or for the unwholesome backroom and weary task-work of the city seamstress. The sunlight was fading from the higher hill-tops of Skye and Glenelg as we bade farewell to the lonely shieling and the hospitable island girl.
The evening deepened as we hurried southwards along the scarce visible pathway, or paused for a few seconds to examine some shattered block, bulky as a Highland cottage, that had fallen from the precipice above. Now that the whole landscape lay equally in shadow, one of the more picturesque peculiarities of the continuous rampart came out more strongly as a feature of the scene than when a strip of shade rested along the face of the rock, imparting to it a retiring character, and all was sunshine beyond. A thick bed of white sandstone, as continuous as the rampart itself, runs nearly horizontally about midway in the precipice for mile after mile, and, standing out in strong contrast with the dark-colored trap above and below, reminds one of a belt of white hewn work in a basalt house front, or rather,—for there occurs above a second continuous strip, of an olive hue, the color assumed, on weathering by a bed of amygdaloid,—of a piece of dingy old-fashioned furniture, inlaid with one stringed belt of bleached holly, and another of faded green-wood. At some of the more accessible points I climbed to the line of white belting, and found it to consist of the same soft quartzy sandstone that in the Bay of Laig furnishes the musical sand. Lower down there occur, alternating with the trap, beds of shale and of blue clay, but they are lost mostly in the talus. Ill adapted to resist the frosts and rains of winter, their exposed edges have mouldered into a loose soil, now thickly covered over with herbage; and, but for the circumstance that we occasionally find them laid bare by a water-course, we would scarce be aware of their existence at all. The shale exhibits everywhere,as on the opposite side of theRu-Stoir, faint impressions of a minute shell resembling a Cyclas, and ill-preserved fragments of fish-scales. The blue clay I found at one spot where the pathway had cut deep into the hill-side, richly charged with bivalves of the species I had seen so abundant in the resembling clay of the Bay of Laig; but the closing twilight prevented me from ascertaining whether it also contained the characteristic univalves of the deposit, and whether its shells,—for they seem identical with those of the altered shales of theRu-Stoir,—might not be associated, like these, with reptilian remains. Night fell fast, and the streaks of mist that had mottled the hills at sunset began to spread gray over the heavens in a continuous curtain; but there was light enough left to show me that the trap became more columnar as we neared our journey's end. One especial jutting in the rock presented in the gloom the appearance of an ancient portico, with pediment and cornice, such as the traveller sees on the hill-sides of Petræa in front of some old tomb; but it may possibly appear less architectural by day. At length, passing from under the long line of rampart, just as the stars that had begun to twinkle over it were disappearing, one after one, in the thickening vapor, we reached the little bay of Kildonan, and found the boat waiting us on the beach. My friend the minister, as I entered the cabin, gathered up his notes from the table, and gave orders for the tea-kettle; and I spread out before him—a happy man—an array of fossils new to Scotch Geology. No one not an enthusiastic geologist or a zealous Roman Catholic can really know how vast an amount of interest may attach to a few old bones. Has the reader ever heard how fossil relics once saved the dwelling of a monk, in a time of great general calamity, when all his other relics proved of no avail whatever?
Thomas Campbell, when asked for a toast in a society of authors, gave the memory of Napoleon Bonaparte; significantly adding, "he once hung a bookseller." On a nearly similar principle I would be disposed to propose among geologists a grateful bumper in honor of the revolutionary army that besieged Maestricht. That city, some seventy-five or eighty years ago, had its zealous naturalist in the person of M. Hoffmann, a diligent excavator in the quarries of St. Peter's mountain, long celebrated for its extraordinary fossils. Geology, as a science, had no existence at the time; but Hoffmann was doing, in a quiet way, all he could to give it a beginning;—he was transferring from the rock to his cabinet, shells, and corals, and crustacea, and the teeth and scales of fishes, with now and then the vertebræ, and now and then the limb-bone, of a reptile. And as he honestly remunerated all the workmen he employed, and did no manner of harm to any one, no one heeded him. On one eventful morning, however, his friends the quarriers laid bare a most extraordinary fossil,—the occipital plates of an enormous saurian, with jaws four and a half feet long, bristling over with teeth, likechevaux de frise; and after Hoffmann, who got the block in which it lay embedded, cut out entire, and transferred to his house, had spent week after week in painfully relieving it from the mass, all Maestricht began to speak of it as something really wonderful. There is a cathedral on St. Peter's mountain,—the mountain itself is church-land; and the lazy canon, awakened by the general talk, laid claim to poor Hoffmann's wonderful fossil ashisproperty. He was lord of the manor, he said, and the mountain and all that it contained belonged to him. Hoffmann defended his fossil as he best could in an expensive lawsuit; but the judges found the law clean against him; the huge reptile head was declared to be "treasure trove"escheat to the lord of the manor; and Hoffmann, half broken-hearted, with but his labor and the lawyer's bills for his pains, saw it transferred by rude hands from its place in his museum, to the residence of the grasping churchman. The huge fossil head experienced the fate of Dr. Chalmer's two hundred churches. Hoffmann was a philosopher, however, and he continued to observe and collect as before; but he never found such another fossil; and at length, in the midst of his ingenious labors, the vital energies failed within him, and he broke down and died. The useless canon lived on. The French Revolution broke out; the republican army invested Maestricht; the batteries were opened; and shot and shell fell thick on the devoted city. But in one especial quarter there alighted neither shot nor shell. All was safe around the canon's house. Ordinary relics would have availed him nothing in the circumstances,—no, not "the three kings of Cologne," had he possessed the three kings entire, or the jaw-bones of the "eleven thousand virgins;" but there was virtue in the jaw-bones of the Mosasaurus, and safety in their neighborhood. The Frenchsavans, like all the othersavansof Europe, had heard of Hoffmann's fossil, and the French artillery had been directed to play wide of the place where it lay. Maestricht surrendered; the fossil was found secreted in a vault, and sent away to theJardin des Plantesat Paris, maugre the canon, to delight there the heart of Cuvier; and the French, generously addressing themselves to the heirs of Hoffmann as its legitimate owners, made over to them a considerable sum of money as its price. They reversed the finding of the Maestricht judges; and all save the monks of St. Peter's have acquiesced in the justice of the decision.