I marked, from the top of the coach, about two miles to the north-east of Dingwall, beds of a deep gray sandstone, identical in color and appearance with some of the gray sandstones of the Middle Old Red of Forfarshire, and learned that quarries had lately been opened in these beds near Montgerald. The Old Red Sandstone lies in immense development on the flanks of Ben-Wevis; and it is just possible that the analogue of the gray flagstones of Forfar may be found among its upper beds. If so, the quarriers should be instructed to look hard for organic remains,—the broad-headed Cephalaspis, so characteristic of the formation, and the huge Crustacean, its contemporary, that disported in plates large as those of the steel mail of the later ages of chivalry. The geologists of Dingwall,—if Dingwall has yet got its geologists,—might do well to attempt determining the point. I found the science much in advance in Cromarty, especially among the ladies,—its great patronizers and illustrators everywhere,—and, in not a few localities, extensive contributors to its hoards of fact. Just as I arrived, there was a pic-nic party of young people setting out for the Lias of Shandwick. They spent the day among its richly fossiliferous shales and limestones, and brought back with them in the evening, Ammonites and Gryphites enough to store a museum. Cromarty had been visited during the summer by geologists speaking a foreign tongue, but thoroughly conversant with the occult yet common language of the rocks, and deeply interested in the stories which the rocks told. The vessels in which the Crown Prince of Denmark voyaged to the Faroe Isles had been for some time in the bay; and the Danes, his companions, votaries of the stony science, zealously plied chisel and hammer among the Old Red Sandstones of the coast. A townsman informed me that he had seen a Danish Professor hammering like the tutelary Thor of his country among the nodules in which I had found the first Pterichthys and first Diplacanthus ever disinterred; and that the Professor, ever and anon as he laid open a specimen, brought it to a huge smooth boulder, on which there lay a copy of the "Old Red Sandstone," to ascertain from the descriptions and prints its family and name. Shall I confess that the circumstance gratified me exceedingly? There are many elements of Discord among mankind in the present time, both at home and abroad,—so many, that I am afraid we need entertain no hope of seeing an end, in at least our day, to controversy and war. And we should be all the better pleased, therefore, to witness the increase of those links of union,—such as the harmonizing bonds of a scientific sympathy,—the tendency of which is to draw men together in a kindly spirit, and the formation of which involves no sacrifice of principle, moral or religious. I do not think that the foreigner, after geologizing in my company, would have had any very vehement desire, in the event of a war, to cut me down, or to knock me on the head. I am afraid this chapter would require a long apology, and for a long apology space is wanting. But there will be no egotism, and much geology, in my next.
CHAPTER XI
Ichthyolite Beds—An interesting Discovery—Two Storeys of Organic Remains in the Old Red Sandstone—Ancient Ocean of Lower Old Red—Two great Catastrophes—Ancient Fish Scales—Their skilful Mechanism displayed by examples—Bone Lips—Arts of the Slater and Tiler as old as Old Red Sandstone—Jet Trinkets—Flint Arrow-heads—Vitrified Forts of Scotland—Style of grouping Lower Old Red Fossils—Illustration from Cromarty Fishing Phenomena—Singular Remains of Holoptychius—Ramble with Mr. Robert Dick—Color of the Planet Mars—Tombs never dreamed of by Hervey—Skeleton of the Bruce—Gigantic Holoptychius—"Coal money Currency"—Upper Boundary of Lower Old Red—Every one may add to the Store of Geological Facts—Discoveries of Messrs. Dick and Peach.
I spent one long day in exploring the ichthyolite beds on both sides the Cromarty Frith, and another long day in renewing my acquaintance with the Liasic deposit at Shandwick. In beating over the Lias, though I picked up a few good specimens, I acquired no new facts; but in re-examining the Old Red Sandstone and its organisms I was rather more successful. I succeeded in eliciting some curious points not yet recorded, which, with the details of an interesting discovery made in the far north in this formation, I may be perhaps able to weave into a chapter somewhat more geological than my last.
Some of the readers of my little work on the Old Red Sandstone will perhaps remember that I described the organisms of that ancient system as occurring in the neighborhood of Cromarty mainly on one platform, raised rather more than a hundred feet over the great Conglomerate; and that on this platform, as if suddenly overtaken by some wide-spread catastrophe, the ichthyolites lie by thousands and tens of thousands, in every attitude of distortion and terror. We see the spiked wings of the Pterichthys elevated to the full, as they had been erected in the fatal moment of anger and alarm, and the bodies of the Cheirolepis and Cheiracanthus bent head to tail, in the stiff posture into which they had curled when the last pang was over. In various places in the neighborhood the ichthyolites are found in situ in their coffin-like nodules, where it is impossible to trace the relation of the beds in which they occur to the rocks above and below; and I had suspected for years that in at least some of the localities, they could not have belonged to the lower platform of death, but to some posterior catastrophe that had strewed with carcasses some upper platform. I had thought over the matter many a time and oft when I should have been asleep,—for it is marvellous how questions of the kind grow upon a man; and now, selecting as a hopeful scene of inquiry the splendid section under the Northern Sutor, I set myself doggedly to determine whether the Old Red Sandstone in this part of the country has not at least its two storeys of organic remains, each of which had been equally a scene of sudden mortality. I was entirely successful. The lower ichthyolite bed occurs exactly one hundred and fourteen feet over the great Conglomerate; and three hundred and eighteen feet higher up I found a second ichthyolite bed, as rich in fossils as the first, with its thorny Acanthodians twisted half round, as if still in the agony of dissolution, and its Pterichthyes still extending their spear-like arms in the attitude of defence. The discovery enabled me to assign to their true places the various ichthyolite beds of the district. Those in the immediate neighborhood of the town, and a bed which abuts on the Lias at Eathie, belong to the upper platform; while those which appear in Eathie Burn, and along the shores at Navity, belong to the lower. The chief interest of the discovery, however, arises from the light which it throws on the condition of the ancient ocean of the Lower Old Red, and on the extreme precariousness of the tenure on which the existence of its numerous denizens was held. In a section of little more than a hundred yards there occur at least two platforms of violent death,—platforms inscribed with unequivocal evidence of two great catastrophes which over wide areas depopulated the seas. In the Old Red Sandstone of Caithness there are many such platforms: storey rises over storey; and the floor of each bears its closely-written record of disaster and sudden extinction. Pompeii in this northern locality lies over Herculaneum, and Anglano over both. We cease to wonder why the higher order of animals should not have been introduced into a scene of being that had so recently arisen out of chaos, and over which the reign of death so frequently returned. In a somewhat different sense from that indicated by the poet of the "Seasons,"
"As yet the trembling year was unconfirmed,
And winter oft at eve resumed the gale."
Lying detached in the stratified clay of the fish-beds, there occur in abundance single plates and scales of ichthyolites, which, as they can be removed entire, and viewed on both sides, illustrate points in the mechanism of the creatures to which they belonged that cannot be so clearly traced in the same remains when locked up in stone. There is a vast deal of skilful carpentry exhibited—if carpentry I may term it—in the coverings of these ancient ichthyolites. In the commoner fish of our existing seas the scales are so thin and flexible,—mere films of horn,—that there is no particularly nice fitting required in their arrangement. The condition, too, through which portions of unprotected skin may be presented to the water, as over and between the rays of the fins, and on the snout and lips, obviates many a mechanical difficulty of the earlier period, when it was a condition, as the remains demonstrate, that no bit of naked skin, should be exposed, and when the scales and plates were formed, not of thin horny films, but of solid pieces of bone. Thin slates lie on the roof of a modern dwelling, without any nice fitting;—they are scales of the modern construction: but it required much nice fitting to make thick flagstones lie on the roof of an ancient cathedral;—they, on the other hand, were scales of the ancient type. Again, it requires no ingenuity whatever, to suffer the hands and face to go naked,—and such is the condition of our existing fish, with their soft skinny snouts and membranous fins; but to cover the hands with flexible steel gauntlets, and the face with such an iron mask as that worn by the mysterious prisoner of Louis XIV., would require a very large amount of ingenuity indeed; and the ancient ichthyolites of the Old Red were all masked and gauntleted. Now the detached plates and scales of the stratified clay exhibit not a few of the mechanical contrivances through which the bony coverings of these fish were made to unite—as in coats of old armor—great strength with great flexibility. The scales of the Osteolepis and Diplopterus I found nicely bevelled atop and at one of the sides; so that where they overlapped each other,—for at the joints not a needle-point could be insinuated,—the thickness of the two scales equalled but the thickness of one scale in the centre, and thus an equable covering was formed. I brought with me some of these detached scales, and they now lie fitted together on the table before me, like pieces of complicated hewn work carefully arranged on the ground ere the workman transfers them to their place on the wall. In the smaller-scaled fish, such as the Cheiracanthus and Cheirolepis, a different principle obtained. The minute glittering rhombs of bone were set thick on the skin, like those small scales of metal sewed on leather, that formed an inferior kind of armor still in use in eastern nations, and which was partially used in our own country just ere the buff coat altogether superseded the coat of mail. I found a beautiful piece of jaw in the clay, with the enamelled tusks bristling on its brightly enamelled edge, like iron teeth in an iron rake. Mr. Parkinson expresses some wonder, in his work on fossils, that in a fine ichthyolite in the British Museum, not only the teeth should have been preserved, but also the lips; but we now know enough of the construction of the more ancient fish, to cease wondering. The lips were formed of as solid bone as the teeth themselves, and had as fair a chance of being preserved entire; just as the metallic rim of a toothed wheel has as fair a chance of being preserved as the metallic teeth that project from it. I was interested in marking the various modes of attachment to the body of the animal which the detached scales exhibit. The slater fastens on his slates with nails driven into the wood: the tiler secures his tiles by means of a raised bar on the under side of each, that locks into a corresponding bar of deal in the framework of the roof. Now in some of the scales I found the art of the tiler anticipated; there were bars raised on their inner sides, to lay hold of the skin beneath; while in others it was the art of the slater that had been anticipated,—the scales had been slates fastened down by long nails driven in slantwise, which were, however, mere prolongations of the scale itself. Great truths may be repeated until they become truisms, and we fail to note what they in reality convey. The great truth that all knowledge dwelt without beginning in the adorable Creator must, I am afraid, have been thus common-placed in my mind; for at first it struck me as wonderful that the humble arts of the tiler and slater should have existed in perfection in the times of the Old Red Sandstone.
I had often remarked amid the fossiliferous limestones of the Lower Old Red, minute specks and slender veins of a glossy bituminous substance somewhat resembling jet, sufficiently hard to admit of a tolerable polish, and which emitted in the fire a bright flame, I had remarked, further, its apparent identity with a substance used by the ancient inhabitants of the northern part of the country in the manufacture of their rude ornaments, as occasionally found in sepulchral urns, such as beads of an elliptical form, and flat parallelograms, perforated edge-wise by some four or five holes a-piece; but I had failed hitherto in detecting in the stone, portions of sufficient bulk for the formation of either the beads or the parallelograms. On this visit to the ichthyolite beds, however, I picked up a nodule that inclosed a mass of the jet large enough to admit of being fashioned into trinkets of as great bulk as any of the ancient ones I have yet seen, and a portion of which I succeeded in actually forming into a parallelogram, that could not have been distinguished from those of our old sepulchral urns. It is interesting enough to think, that these fossiliferous beds, altogether unknown to the people of the country for many centuries, and which, when I first discovered them, some twelve or fourteen years ago, were equally unknown to geologists, should have been resorted to for this substance, perhaps thousands of years ago, by the savage aborigines of the district. But our antiquities of the remoter class furnish us with several such facts. It is comparatively of late years that we have become acquainted with the yellow chalk-flints of Banffshire and Aberdeen; though before the introduction of iron into the country they seem to have been well known all over the north of Scotland. I have never yet seen a stone arrow-head found in any of the northern localities, that had not been fashioned out of this hard and splintery substance,—a sufficient proof that our ancestors, ere they had formed their first acquaintance with the metals, were intimately acquainted with at least the mechanical properties of the chalk-flint, and knew where in Scotland it was to be found. They were mineralogists enough, too, as their stone battle-axes testify, to know that the best tool-making rock is the axe-stone of Werner; and in some localities they must have brought their supply of this rather rare mineral from great distances. A history of those arts of savage life, as shown in the relics of our earlier antiquities, which the course of discovery sereved thoroughly to supplant, but which could not have been carried on without a knowledge of substances and qualities afterwards lost, until re-discovered by scientific curiosity, would form of itself an exceedingly curious chapter. The art of the gun-flint maker (and it, too, promises soon to pass into extinction) is unquestionably a curious one, but not a whit more curious or more ingenious than the art possessed by the rude inhabitants of our country eighteen hundred years ago, of chipping arrow-heads with an astonishing degree of neatness out of the same stubborn material. They found, however, that though flint made a serviceable arrow-head, it was by much too brittle for an adze or battle-axe; and sought elsewhere than among the Banffshire gravels for the rock out of which these were to be wrought. Where they found it in our northern provinces I have not yet ascertained. It is but a short time since I came to know that they were beforehand with me in the discovery of the bituminous jet of the Lower Old Red Sandstone, and were excavators among its fossiliferous beds. The vitrified forts of the north of Scotland give evidence of yet another of the obsolete arts. Before the savage inhabitants of the country were ingenious enough to know the uses of mortar, or were furnished with tools sufficiently hard and solid to dress a bit of sandstone, they must have been acquainted with the chemical fact, that with the assistance of fluxes, a pile of stones could be fused into a solid wall, and with the mineralogical fact, that there are certain kinds of stones which yield much more readily to the heat than others. The art of making vitrified forts was the art of making ramparts of rock through a knowledge of the less obstinate earths and the more powerful fluxes. I have been informed by Mr. Patrick Duff of Elgin, that he found, in breaking open a vitrified fragment detached from an ancient hill-fort, distinct impressions of the serrated kelp-weed of our shores,—the identical flux which, in its character as the kelp of commerce, was so extensively used in our glass-houses only a few years ago.