Fig. 28.—Bird’s-eye view of Santorin during the volcanic eruption of February, 1866. (Lyell.)a.Therasia.b.The northern entrance, 1068 feet deep.c.Thera.d.Mount St. Elias, rising 1887 feet above the sea.e.Aspronisi.f.Little Kaimeni.g.New Kaimeni.h.Old Kaimeni.i.Aphroessa.k.George.
Fig. 28.—Bird’s-eye view of Santorin during the volcanic eruption of February, 1866. (Lyell.)
a.Therasia.b.The northern entrance, 1068 feet deep.c.Thera.d.Mount St. Elias, rising 1887 feet above the sea.e.Aspronisi.f.Little Kaimeni.g.New Kaimeni.h.Old Kaimeni.i.Aphroessa.k.George.
The neighborhood of Santorin in the Grecian Archipelago has been noted from very remote times as the theatre of submarine eruptions. This island, which is itself to all appearance the crater of a vast volcano, has the form of a crescent, and, with the aid of two smaller islands which stretch across between the horns of the crescent, encloses an almost circular bay. We learn from Pliny that in the year 186 before Christ, within this bay an island roseup which was called Hiera or the Sacred island. It was twice enlarged during the Christian era, once in 726, and again in 1427, and still exists under the name of Palaia Kaimeni, that is to say, the Old Burnt Island. In 1573 a second island made its appearance, and received the name of the Little Burnt Island, Mikra Kaimeni. In 1707 and 1709, a third island was thrown up, and was distinguished from the other two as Nea Kaimeni, the New Burnt Island. Lastly, in 1866 the hidden volcanic power again became active, and two new vents were formed, called respectively Aphroessa and George. “At the end of January,” writes Sir Charles Lyell, “the sea had been observed in a state of ebullition off the southwest coast, and part of the Channel between New and Old Kaimeni, marked seventy fathoms in the Admiralty chart, had become, on February the eleventh, only twelve fathoms deep. According to M. Julius Schmidt, a gradual rising of the bottom went on until a small island made its appearance called afterward Aphroessa. It seems to have consisted of lava pressed upward and outward almost imperceptibly by steam, which was escaping at every pore through the hissing scoriaceous crust. ‘It could be seen,’ says Commander Lindesay Brine, R. N., ‘through the fissures in the cone that the rocks within were red hot, but it was not till later that an eruption began.’ On February the eleventh the village of Vulcano on the southeast coast, where there had been a partial sinking of the ground, was in great part overwhelmed by the materials cast out from a new vent which opened in that neighborhood, and to which the name of George was given, which finally, according to Schmidt, became about two hundred feet high.
“Commander Brine having ascended on February the twenty-eighth, 1866, to the top of the crater of Nea Kaimeni, about three hundred and fifty feet high, looked down upon the new vent then in full activity. The whole of thecone was swaying with an undulating motion to the right and left, and appeared sometimes to swell to nearly double its size and height, to throw out ridges like mountain spurs, till at last a broad chasm appeared across the top of the cone, accompanied by a tremendous roar of steam and the shooting up from the new crater, to the height of from fifty to a hundred feet, of tons of rock and ash mixed with smoke and steam. Some of these which fell on Mikra Kaimeni, at a distance of six hundred yards from the crater, measured thirty cubic feet. This effort over, the ridges slowly subsided, the cone lowered and closed in, and then, after a few minutes of comparative silence, the struggle would begin again with precisely similar sounds, action, and result. Threads of vapor escaping from the old crater of Nea Kaimeni proved that there was a subterranean connection between the new and the old vents. Aphroessa, of which the cone was at length raised to a height of more than sixty feet, was united in August with the main island. This was due in part at least to the upheaval of the bottom of the sea, which is now only seven fathoms deep in the channel dividing the New and Old Kaimenis, whereas in the Admiralty chart the soundings gave a hundred fathoms.”97
Earthquakes and volcanos proceed from the same common cause—Recent earthquakes in New Zealand—Vast tracts of land permanently upraised—Earthquakes of Chili in the present century—Crust of the Earth elevated—Earthquake of Cutch in India, 1819—Remarkable instance of subsidence and upheaval—Earthquake of Calabria, 1783—Earthquake of Lisbon, 1755—Great destruction of life and property—Earthquake of Peru, August, 1868—General scene of ruin and devastation—Great sea wave—A ship with all her crew carried a quarter of a mile inland—Frequency of earthquakes.
T
Thechief effect of volcanic eruptions on the Geological structure of our Globe consists in the accumulation of cinders and molten rock, either upon the Surface of the Earth, or in the crevices and caverns that abound within its solid Crust. Sometimes, indeed, the operations of an active Volcano are accompanied by a movement of upheaval or of subsidence. Thus for instance, we have seen that a portion of the Italian coast was elevated when Monte Nuovo was thrown up, that the town of Tomboro was submerged on the occasion of the eruption of Sumbawa, and that the bottom of the sea was notably upheaved by the last outbreak of the volcanic fires of Santorini. Nevertheless it appears to be generally the case that when the Crust of the Earth is once burst open, and a means ofescape thus afforded to the fiery agent below,—in other words, when the active volcano is established,—the process of upheaval gives place to that of eruption. But when, as is often the case, no such safety-valve is offered to the surplus energies of the subterranean fires, then the giant power of heat, in its struggle to escape, shakes the foundation of the hills, and uplifts the superincumbent mass of solid rocks.
This theory which ascribes the phenomena of Earthquakes and Volcanos to the same common cause, acting under different circumstances, is now almost universally adopted by Geologists; and it may be briefly enforced by the following considerations. First, though Earthquakes have sometimes occurred far away from any known volcanic region, yet they are more frequent in the neighborhood of active or extinct Volcanos. Secondly, almost all volcanic eruptions are preceded by Earthquakes; and the Earthquakes generally cease, or, at least become less violent, when the subterranean fire breaks out in the form of a Volcano. And, Thirdly, it is plain that the condensed steam which is generated by internal heat, and the expansive power of the heat itself, must, of necessity, when pent up in the caverns of the Earth, tend to produce those very phenomena by which Earthquakes are distinguished.
Let it be observed, however, that while we explain the phenomena in question by the agency of subterranean heat, this doctrine is by no means necessary for the main purpose of our present argument. Whatever may be the cause from which the Earthquake shock proceeds, it is enough for us to show that the Crust of the Earth has been from time to time upraised, and dislocated, and rent asunder in modern times, just as it is supposed in Geological theory, to have been upraised, and dislocated, and rent asunder from time to time in by-gone ages. We will set down a few out of the many examples observed and recorded during the last hundred and twenty years.
When the English colonists settled in New Zealand, about fifty years ago, they were told by the natives that they might expect a great Earthquake every seven years. This alarming prediction has not been literally fulfilled; but it is fully admitted that the total number of such disturbances within the last half century has not fallen short of what it should have been according to the above estimate. During the years 1826 and 1827 several shocks were felt in the neighborhood of Cook Strait, after which it was observed that the sea-shore had been uplifted on the north side of Dusky Bay. So transformed was the outline of the coast that its former features could no longer be recognized; and a small cove called the Jail, which had previously afforded a commodious harbor to vessels, engaged in seal fishing, was completely dried up.
But the most memorable convulsion took place on the night of January the twenty-third, 1855. A tract of land, about as large as Yorkshire, on the southwest coast of the North Island, was permanently upraised from one to nine feet. The harbor of Port Nicholson, together with the valley of the Hutt, was elevated four to five feet; and a sunken rock, regarded before as dangerous to navigators, has remained since the Earthquake three feet above the level of the water. The shock was felt by ships at sea a hundred and fifty miles from the coast; and it is estimated that the whole area affected was not less than three times the extent of the British Islands.
The whole coast of Chili has been subject to great disturbances and changes of level during the present century. In November, 1837, the town of Valdivia was destroyed by an Earthquake, and at the same moment, a whaling vessel, a short distance out at sea, was violently shaken, and lost her masts. The bottom of the sea was afterward found to have been raised in some places more than eight feet; and several rocks appeared high above the water which hadpreviously been covered at all times by the sea. Two years before, in 1835, the town of Conception and several others were reduced to ruins by a like visitation. After the first great convulsion the Earth remained for many days in a state of commotion. More than three hundred lesser shocks were counted from the twentieth of February to the fourth of March. On this occasion, too, the bed of the sea was upheaved; and the whole island of Santa Maria, seven miles in length, was lifted up from eight to ten feet above its former level.
The Earthquake of 1822 was more violent, perhaps, and more striking in its effects, than either of those just mentioned. On the nineteenth of November in that year a sudden convulsive shock was simultaneously felt over a space 1200 miles in length. At Valparaiso, and on either side for a considerable distance, the coast was permanently upheaved. When Mrs. Graham, who was then living on the spot, and who has left us an account of the Earthquake, went down to the shore on the following day, she “found the ancient bed of the sea laid bare and dry, with beds of oysters, mussels, and other shells adhering to the rocks on which they grew, the fish being all dead, and exhaling most offensive effluvia.” Some idea may be formed of the gigantic power here in operation, when it is remembered that to uplift the coast of Chili, it was necessary to move the mighty chain of the Andes, and, amongst the rest, the colossal mass of Aconcagua, 24,000 feet in height. How far this process of upheaval extended out to sea, beneath the bed of the ocean, has not been accurately ascertained: but certain it is that, for a considerable distance, the soundings were found to be shallower than before the Earthquake. It is roughly estimated that the Crust of the Earth was elevated over an extent of 100,000 square miles, or about half the area of France.
On the western coast of India, near the mouth of theriver Indus, is the well-known district of Cutch. In the month of June, 1819, this extensive territory, not less than half the size of Ireland, was violently shaken by an Earthquake, several hundred people were killed, and many towns and villages were laid in ruins. The shocks continued for some days, and ceased only when the outburst of a Volcano seemed to open a vent for the troubled spirit within. But what is particularly worthy of note is that when the Earthquake had passed away, a permanent change was found to have been effected in the level of the surrounding country. The town and fort of Sindree, situated on the eastern arm of the Indus, together with a tract of land 2,000 square miles in extent, were submerged beneath the waters. The principal buildings, however, still remained standing, with their upper parts above the surface; and many of the inhabitants, who had taken refuge in one of the towers attached to the fort, were saved in boats when the Earthquake had ceased. On the other hand, within five miles and a half of this very spot, the level surface of the Earth was upheaved, so as to form a long elevated bank, fifty miles in length and sixteen in breadth, which has been called the Ullah Bund, or the Mound of God. Nine years after this event, Sir Alexander Burnes went out in a boat to the ruins of Sindree, and standing on the summit of the tower, which still rose two or three feet above the surface of the water, he could see nothing around him but a wide expanse of sea, save where a blue streak of land on the edge of the horizon marked the outline of the Ullah Bund. Here was a striking illustration, on a small scale, of those changes which Geologists suppose to have been going on since the world first began; the dry land had been converted into the bed of the sea, and the level plain had been elevated into a mountain ridge.
Toward the close of the last century the province of Calabria, in Southern Italy, was the scene of an Earthquakewhich offers a very apposite illustration of our present argument. This celebrated convulsion is not, however, chiefly remarkable for its violence, or for its duration, or for the extent of the territory moved. In all these respects it has been surpassed by many Earthquakes, experienced in other countries, within the last hundred and fifty years. But the Calabrian Earthquake has an especial claim on our attention, mainly from this unusual circumstance, that the region of disturbance was visited, as Sir Charles Lyell tells us, “both during and after the convulsions, by men possessing sufficient leisure, zeal, and scientific information, to enable them to collect and describe with accuracy such physical facts as throw light on geological questions.”
The shocks were first felt in February, 1783, and continued for nearly four years. Over a very considerable area of country all the common landmarks were removed, large tracts of land were forced bodily down the slopes of mountains; and vineyards, orchards, and cornfields were transported from one site to another; insomuch that disputes afterward arose as to who was the rightful owner of the property that had thus shifted its position. Two farms near Mileto, occupying an extent of country a mile long and half a mile broad, were actually removed for a mile down the valley; and “a thatched cottage, together with large olive and mulberry trees, most of which remained erect, was carried uninjured to this extraordinary distance.” In other places the surface of the Earth heaved like the billows of a troubled sea; many houses were lifted up above the common level, while others subsided below it. Again and again the solid Crust of the Earth was rent asunder, and chasms, gorges, ravines, of various depths, were suddenly produced, in less time than it takes to tell it. Sometimes when the strain was removed, the yawning gulf as quickly closed again, and then houses, cattle, and men were swallowed up in the abyss, leaving not a trace behind. It haseven been recorded—strange though it may seem—that when two shocks rapidly followed one another at the same spot, the people engulphed by the first, were again cast forth by the second, being literally disgorged alive from the jaws of death. About 40,000 persons perished in this dreadful visitation, the greater number being crushed to death beneath the ruins of the towns and villages, others swallowed up in the yawning fissures as they fled across the open country, and others again burned in the conflagrations which almost always followed the shocks of Earthquake.
Everyone has heard of the famous Earthquake of Lisbon. It is chiefly memorable for the extreme suddenness of the shock, for the immense extent of the area affected, and for the amount of havoc and destruction done. On the morning of the fatal day—it was the first of November, 1755—the sun rose bright and cheerful over the devoted city, no symptom of impending danger was visible in the sky above or on the Earth below, and the gay-hearted people were pursuing their accustomed rounds of pleasure or business, when, suddenly, at twenty minutes before ten o’clock, a sound like thunder was heard underground, the Earth was violently shaken, and in another moment, the greater part of the city was lying in ruins. Within the brief space of six minutes, 60,000 people were crushed to death. The mountains in the vicinity of the town were cleft asunder. The waters of the sea first retired from the land, and then rolled back in a huge mountain-like wave fifty feet above the level of the highest tide. A new quay, built entirely of marble, had offered a temporary place of refuge to the terrified inhabitants as they fled from the tumbling ruins of the city. Three thousand people are said to have been collected upon it, when, all at once, it sunk beneath the waves, and not a fragment of the solid masonry, not a vestige of its living freight, was ever seen again. The bottomof the sea where the quay then stood is now a hundred fathoms deep.
From Lisbon as a centre the shock of this Earthquake radiated over an area not less than four times the extent of Europe. Like a great wave it rolled northward, at the rate of twenty miles a minute, upheaving the Earth as it moved along, to the coasts of the Baltic Sea and the German Ocean. The waters of Loch Lomond, in Scotland, were violently disturbed from beneath, and at Kinsale, in Ireland, the sea rushed impetuously into the harbor without a breath of wind, and mounting over the quay, flooded the market-place. Eastward the convulsion was felt as far as the Alps, and westward it extended to the West India Islands, and even to the great lakes of Canada. On the north coast of Africa the disturbance was as violent as in Spain and Portugal; and it is recorded that at a distance of eight leagues from Morocco, the earth opened and swallowed up a considerable town with its inhabitants, to the number of eight or ten thousand people.
Even on the high seas the shock was felt no less distinctly than on dry land. “Off St. Lucar,” says Sir Charles Lyell, “the captain of the ship Nancy felt his vessel so violently shaken, that he thought she had struck the ground, but, on heaving the lead, found a great depth of water. Captain Clark, from Denia, in latitude 36° 24´ N., between nine and ten in the morning, had his ship shaken and strained as if she had struck upon a rock, so that the seams of the deck opened, and the compass was overturned in the binnacle. Another ship, forty leagues west of St. Vincent, experienced so violent a concussion, that the men were thrown a foot and a half perpendicularly up from the deck.” It is worthy of note that this, the most destructive Earthquake recorded in history, was not attended with any volcanic eruption; which goes to confirm our theory that the active Volcano serves as a kind ofsafety-valve for the escape of the struggling powers confined within the Crust of the Earth.98
We must not bring our notice of Earthquakes to an end without at least some brief account of one which has startled the world even since we began to put together the materials of this Volume. On the Western Coast of South America there is a long, narrow strip of land, lying between the lofty crests of the Andes and the shores of the Pacific Ocean, which from the earliest times has been the familiar home of Earthquakes. Toward evening on the thirteenth of August, 1868, this fated region was the scene of a convulsion the most appalling and destructive that has been recorded within the present century. The disturbance was felt in its extreme violence for a distance of 1500 miles along the coast; from Ibarra one degree north of the Equator to Iquique more than twenty degrees south. In ten minutes from the first shock, 20,000 people perished, and a vast amount of property, roughly estimated at sixty millions sterling, was utterly destroyed. Many thriving towns—Iquique, Mexillones, Pisagua, Arica, Ylo, Chala, and others—were levelled to the ground. Even the very ruins were not spared. The sea rushed in when the Earthquake shock had ceased, and carried everything before it in one universal wreck: so that in some cases not a vestige remained behind to tell the dismayed survivors where their homesteads once had stood. It might be fancied perhaps that the cities seated aloft in the security of the Eternal Hills were beyond the reach of the convulsion that shook the plain below. But no: Arequipa, far up onthe slopes of the western Cordillera, and Pasco, the highest city in the world, situated on a level with the snowy summit of the Jungfrau, were shattered into fragments with the same violence as the cities of the coast.
The various incidents recorded by the survivors are full of fearful interest. At Iquique, according to one account, about five o’clock in the evening of the thirteenth of August, a rumbling noise was heard, then the earth shook violently for some minutes, then the sea, with a great moan, retired from the shore, and rearing itself up into a tremendous wave, rushed back upon the land and swept away the town. “I saw,” says one writer, “the whole surface of the sea rise as if a mountain side, actually standing up. Another shock, accompanied with a fearful roar, now took place. I called to my companions to run for their lives on to the Pampa. Too late! With a horrid crash the sea was on us, and at one sweep—one terrible sweep—dashed what was Iquique on to the Pampa. I lost my companions, and in an instant was fighting with the dark water. The mighty wave surged and roared and leaped. The cries of human beings and animals were dreadful. A mass of wreck covered me and kept me down, and I was fast drowning when the sea threw me on to a beam, but a nail piercing my coat, the timber rolled me again under, and I lost all sense. I suppose, as in all such cases, I must have struggled after sensation had left me, for when returning consciousness came I was grasping under one arm a large plank. Looking round, all was wreck and desolation. In a moment I was by a returning wave swept into the bay, and meeting a mass of broken timber, I was struck a fearful blow on the chin, and the broken end of the plank passed through my thigh. I knew no more until I found myself on the Pampa, and all dark around me. I was without trousers, coat, shoes, or hat. Trying to collect myself, I thought of another wave, and crawled away to themountain side, scooped a hole in the ground, and got in; here, wet and shivering, I spent the night. My wound bled freely. In the morning I looked out and found Iquique gone, all but a few houses round the church.”
A good deal of shipping was lying in the bay of Arica. When the waters first receded the vessels were all carried out to sea, chains, cables, and anchors snapping asunder like packthread. A moment, afterward they were borne back irresistibly by the returning wave, and dashed to pieces on the coast. One more fortunate than the rest, the Wateree, a vessel of war belonging to the United States Government, was caught up on the crest of the wave, and with the loss of only one man, was landed high and dry among the sand-hills a quarter of a mile from the shore.
Before the Earthquake, Arequipa was a prosperous town of 30,000 inhabitants. It enjoyed a considerable trade, and, in importance as well as size, it was regarded as the third city of Peru, being inferior only to Lima and Cuzco. The houses were constructed with especial regard to security against the shock of Earthquakes. They were but one story high, built of solid stone, and massive to an extraordinary degree. But these precautions, though the fruit of long experience, were all of no avail. At Sunset on the fatal thirteenth of August the populous and thriving city of Arequipa was little better than a heap of ruins. “Not a church is left standing,” writes an eye-witness, “not a house habitable. The shock commenced at twenty minutes past five in the afternoon, and lasted six or seven minutes. The houses being solidly built and of one story, resisted for one minute, which gave the people time to rush into the middle of the streets, so that the mortality, although considerable, is not so great as might have been expected. If the Earthquake had occurred at night, few indeed would have been left to tell the story. As it is, the prisoners in the public prison, and the sick in the hospital, have perished.The Earthquake commenced with an undulating movement, and as the shock culminated, no one could keep his feet: the houses rocked as a ship in the trough of the sea, and came crumbling down. The shrieks of the women, the crash of falling masonry, the upheaving of the earth, and the clouds of blinding dust, made up a scene that cannot be described. We had nineteen minor shocks the same night, and the earth still continues in motion. Nothing has as yet been done toward disinterring the dead; but I do not think any are buried alive, as certain death must have been the fate of all those who were not able to get into the street. The earth has opened in all the plains around, and water has appeared in various places.”99
These are a few typical examples of the more violent convulsions by which the Crust of the Earth has been disturbed within little more than a century; and they leave no doubt as to the kind of changes which may fairly be ascribed to similar agency in the past history of the Globe. Nor must it be supposed that, because our examples are few in number, the Earthquake is itself a rare and exceptional event. On the contrary, the state of partial disturbance and convulsion would seem to be the natural and ordinary condition of our planet. From the interesting Catalogue drawn up by Mr. Mallet, it appears that, in our own times, the number of Earthquakes actually observed and recorded is, on an average, not less than from two to three every week. Now this catalogue cannot represent more than one-third of the Globe: for the disturbanceswhich take place in the profound depths of the ocean must for the most part escape observation, and many parts even of the inhabited Earth are still beyond the reach of scientific researches. It is, therefore, quite a reasonable speculation of Sir Charles Lyell, that “scarcely a day passes without one or more shocks being experienced in some part of the Globe.”
Moreover, in Mr. Mallet’s Catalogue no account is taken of those minor vibrations or tremblings of the Earth’s Crust, which are not attended by any striking or noteworthy event. And yet such phenomena, when often repeated, may produce a very important change of level, and are far more frequent than most persons would be likely to suppose. In our quiet region of the Globe people are too apt to take for granted the general stability of the Earth: but in other countries the inhabitants, warned by long experience, are no less deeply impressed with a conviction of its instability. Sir John Herschel says that, in the volcanic regions of Central and Southern America, “the inhabitants no more think of counting Earthquake shocks, than we do of counting showers of rain:” nay, he adds that, “in some places along the coast a shower is a greater variety.” And in Sicily, we are told they make provision against movements of the Earth’s Crust, just as we make provision against lightning and storms; so much so that it is quite a common thing for architects to advertise their houses as Earth-quake-proof.
Gentle movements of the Earth’s Crust within historic times—Roman roads and temples submerged in the bay of Baiæ—Temple of Jupiter Serapis—Singular condition of its columns—Proof of subsidence and subsequent upheaval—Indications of a second subsidence now actually taking place—Gradual upheaval of the coast of Sweden—Summary of the evidence adduced to establish this fact—Subsidence of the Earth’s Crust on the west coast of Greenland—Recapitulation.
S
Sofar we have spoken of the disturbance of the Earth’s Crust in modern times by sudden and violent convulsions. But there are many phenomena with which the Geologist is familiar, that cannot be fairly accounted for unless by supposing that the surface of the Earth was often elevated and depressed in ancient times, without any sudden shock, by a slow and almost insensible movement. And, accordingly, gentle undulations of this kind enter largely into that general theory of Geology which we have been attempting to draw out and illustrate. It may be asked, therefore, if we are able to support this part of our system by examples of similar phenomena occurring within the period of history. In reply, we shall endeavor to set forth, as briefly as we can, some of the evidencewhich has recently come to light on this subject, and which seems to us not less conclusive than it is interesting and unexpected.
In the bay of Baiæ, to the west of Naples, two ancient Roman roads may be distinctly traced, at the present day, for a considerable distance, permanently submerged beneath the waters. There are, also, in the same neighborhood, the ruins of the temple of Neptune and of the temple of the Nymphs, both likewise submerged. “The columns of the former edifice stand erect in five feet of water, the upper portions just rising to the surface;100the pedestals are supposed to be buried in the mud below.” Again, on the opposite side of Naples, near Sorrento, “a road with fragments of Roman buildings, is covered to some depth by the sea;”101and in the island of Capri, at the opening of the bay of Naples, one of the palaces of Tiberius is also under water. Here, therefore, it is clear that the Crust of the Earth has subsided over a very considerable area; since what is now the bed of the sea, was in the days of the Romans dry land, traversed by roads, and dotted over with buildings. That the subsidence was slow and gradual may be inferred, partly from the absence of any record or tradition of a sudden convulsion producing such a change, and partly, too, from the unshaken and undisturbed condition of the monuments themselves.
But while this conclusion falls in most happily with our present argument, it would seem on further examination to bring with it a very serious difficulty. For, while those ancient monuments testify that the Crust of the Earth in this locality hassubsided, the structure of the sea-coast, interpreted according to Geological principles, would indicate, on the contrary, that the Crust of the Earth has beenupheaved. Close to the sea, at the present day, on the bay of Baiæ, there is a low, level tract of fertile land, and at a littledistance inland, a lofty range of precipitous cliffs, eighty feet high, parallel to the line of the coast. This fertile tract, lying between the sea-beach and the perpendicular cliffs, is about twenty feet above the sea level, and is composed of regularly stratified deposits abounding in marine shells of recent species, together with works of human art, such as tiles, squares of mosaic pavement, fragments of bricks, and sculptured ornaments. Upon these facts a Geologist would pronounce without hesitation:—First, that at some period since the district around Naples was first inhabited by man, the waters of the sea washed the base of the perpendicular cliffs; secondly, that the strata in which we now find the recent marine shells, and the remains of man’s workmanship, were formed during that period by the process of deposition at the bottom of the sea; and thirdly, that at some subsequent time, by an upheaval of the Earth’s Crust, these strata were lifted up so as to form a pretty considerable area of dry land, fit for agriculture and the arts of life.
Does it not seem, therefore, that we have here a direct contradiction between the evidence of ancient Roman buildings and the inferences of modern Geology? Doubtless, they both agree in the main point about which we are concerned just now, that the Crust of the Earth has been moved in recent times on the shores of the bay of Naples; but according to the testimony of the Roman temples, now covered by water, this movement has been one ofsubsidence, while, according to the inferences of Geological theory, it has been one ofupheaval. This apparent contradiction seems to call for some elucidation.
If we were left in this matter to mere conjecture, we might offer the following hypothesis as a fair and reasonable solution. We might suppose that since the days of the Roman Empire, there have beentwo successive movementsof the Earth’s Crust in the neighborhood of Naples; first, amovement of subsidence, by which the ancient temples and roads were submerged to a considerable depth beneath the sea; afterward, a movement of upheaval, by which the marine strata were lifted up. If this second movement were exactly equal to the first, it is plain that the ancient roads and buildings would have been just restored to their former level. But let us suppose that the amount of upheaval was something less than the amount of previous subsidence, and we should have these roads and buildings still submerged, as they are in point of fact, in a few feet of water. By such an hypothesis, therefore, the two classes of phenomena might be brought into perfect harmony.
But we are not obliged to take refuge in hypothesis: for it is now distinctly proved by a very curious kind of evidence, that the Crust of the Earth in and about the bay of Baiæ, has been successively depressed and upraised since the third century of the Christian era; nay more, that the subsidence in the first case was greater than the subsequent upheaval. Near Pozzuoli, on the level tract of land which, as we have said, intervenes between the sea and the lofty range of inland cliffs, are to be seen at the present day the ruins of a splendid Roman edifice, usually called the temple of Jupiter Serapis, though, according to some writers, it was not a temple at all, but a public establishment for baths. These ruins first attracted attention about the middle of the last century. Three magnificent marble columns were still standing erect, with their lower parts buried in the stratified deposits already described, and their upper portions, which projected above the surface of the land, partly concealed by bushes. When the soil was removed the original plan of the building could be distinctly traced. “It was of a quadrangular form, seventy feet in diameter, and the roof had been supported by forty-six noble columns, twenty-four of granite and the rest of marble.” Many of the pillars have been shattered in the course of time, andlie strewn in fragments on the pavements. The three which are still standing erect, are upward of forty feet in height, each carved out of a solid block of marble; and, what is chiefly to our purpose, they exhibit, curiously inscribed on their surface, memorials of the physical changes in which they have borne a part.
The base of these lofty columns is, at present, slightly below the level of the sea. Their outer surface is smooth for about twelve feet above the pedestals; then, for the next nine feet the marble is everywhere bored by a well-known species of mussel, which it is certain can live only in the sea. Above this band of perforations the pillars again present a smooth surface, and continue smooth to the top. The first inference from these facts is, that the columns in question must have been at one time submerged to a height of twenty-one feet above the pedestals; otherwise they could not have been bored at that height by a species of animal that can only exist in sea-water. Since that time, therefore, the land at this spot must have been upraised twenty-one feet. Furthermore, the temple of Jupiter was certainly not built at the bottom of the sea, but upon dry land; therefore, after the temple had been built, the Crust of the Earth must have subsided at least twenty-one feet. Once more: as the floor of the temple is now somewhat below the level of the sea, and as it is not very likely it was at first so built, we may fairly infer that it is now lower than it originally stood; and consequently, that the total amount of upheaval has not been equal to the total amount of subsidence. Though we cannot fix the exact date at which the subsidence began, it was probably not earlier than the third century; for in the atrium of the temple is an inscription recording that it was adorned with precious marbles by the emperor Septimus Severus.
It cannot be supposed for a moment that these changes were effected by a rise and fall in the level of the sea ratherthan by a movement of the Earth’s Crust. A permanent change in the level of the Mediterranean, in any given locality, would, of necessity, imply a change of level over its entire extent; and therefore, if the phenomena exhibited in the bay of Baiæ arose from such a cause, we should meet with phenomena of the same kind along the whole length of the Italian coast. Now, in point of fact, no such changes of level are elsewhere apparent; and consequently, they must be ascribed in the bay of Baiæ, not to an upward and downward movement of the sea, but to an upward and downward movement of the land.
We must not omit to state, before leaving the subject, that it is now ascertained, by a series of accurate observations, that the Crust of the Earth in this interesting locality is once again slowly and gradually subsiding. At the beginning of the century the platform of the temple stood at about the level of the sea; it is now more than a foot below it. Nay, this second subsidence appears to have begun even before the present century. “In the year 1813,” writes a modern traveller, “I resided for four months in the Capuchin convent of Pozzuoli, which is situated between the road from Naples and the sea, at the entrance of the town of Pozzuoli. In the Capuchin convents the oldest friar is called ‘il molto reverende,’ and the one who then enjoyed the title in this convent was ninety-three years old. He informed me that, when he was a young man, the road from Naples passed on theseaward sideof the convent; but that, from the gradual sinking of the soil, the road was obliged to be altered to its present course. While I was staying at the convent, the refectory as well as the entrance gate, were from six inches to a foot under water whenever strong westerly winds prevailed, so as to cause the waters of the Mediterranean to rise. Thirty years previously, my old informant stated, such an occurrence never took place. In fact, it is not probable that the builder ofthe convent would have placed the ground-floor so low as to expose to inundation as it now is.”102
On the shores of the Baltic Sea we find another illustration of our theory upon a more extended scale. About a century and a half ago the Swedish naturalist, Celsius, expressed a belief that a remarkable change of level was taking place along the eastern coast of Scandinavia; and he ascribed the change to a subsidence of the waters of the Baltic Sea. This opinion was received at first with no small amount of incredulity; but the arguments of Celsius were plausible and attractive enough to excite a controversy, and the controversy once aroused was not easily set at rest. Accordingly, since his time the facts upon which he relied have been more strictly examined, difficulties have been started and investigated, many new facts, at first unknown or unnoticed, have been brought to light, and the whole question has been rigorously discussed by scientific men. It would be tedious to go through the history of the discussion, or to develop at any length the arguments which in the end have proved successful, involving as they do a multitude of minute observations and nice measurements, made at a great variety of different places with hard-sounding names. But the general result may be readily stated and as readily understood.
It appears that numerous sunken reefs, well known to navigators, have, within the last two centuries, become visible above water; that many ancient ports have become inland towns; that many small islands have become united to one another and to the mainland by grassy plains; that rocky points which in former times just peeped above the water, and afforded refuge only to a solitary sea-bird, are now grown into little islets; and that several of the old fishinggrounds are now deserted for their shallowness, nay, in some cases, altogether dried up. From these facts the inference is plain; either the solid Crust of the Earth has been uplifted, or the waters of the sea have subsided. Now it is certain there has been no subsidence of the sea; for such a subsidence, as we before observed, if it took place at all, should have been general; whereas there are many points on the shores of the Baltic, especially along the coasts of Denmark and Prussia, where it can be proved that no change of level has taken place for centuries. And therefore the phenomena above described we must attribute to an upheaval of the Earth’s Crust.103
Such is the kind of reasoning with which this inquiry has been pursued; and it may now be set down as a received and established fact, that a slow and gradual process of upheaval is going on, at the present day, on the shores of the Baltic Sea, at the rate of from two to four feet in a century; and this is over an area of unknown breadth, and not less than 1000 miles in length. Evidence of a similar kind has lately been adduced to prove that the west coast of Greenland is just now gradually subsiding for a space of more than 600 miles from north to south. “Ancient buildings on low, rocky islands, and on the shore of the mainland, have been gradually submerged, and experience has taught the aboriginal Greenlander never to build his hut near the water’s edge. In one case the Moravian settlers have been obliged more than once to move the poles upon which their large boats were set, and the old poles still remain beneath the water as silent witnesses of the change.”104
It should seem, therefore, that the Crust of the Earth is not that fixed and immovable mass of unyielding rock which it is often supposed to be. Whatever the gigantic power is which lies shut up within it, and which seems, clearlyenough, to be developed in some way or another—perhaps in many ways at once—from internal heat, that power exercises a mighty influence from age to age on the outward form of our planet. Like the wind, indeed, it bloweth where it listeth, and we cannot tell whence it cometh or whither it goeth; but we can hear the sound thereof, and witness its effects when it breaks out now in this quarter of the world, and now in that, bursting open the massive rocks, and furiously vomiting forth whole mountains of smouldering ashes and molten mineral; or again, when, failing to find a vent, it shakes the foundations of the hills, and shivers into fragments the most enduring works of man—castles, temples, palaces,—filling every heart with terror and dismay; or, in fine, when it gently upheaves the bottom of the ocean, or by withdrawing the strain, allows the Crust of the Earth to subside, with a movement so gradual and insensible as to escape the notice of the multitudes who are toiling in the busy cities on its Surface. That phenomena of this kind have been going on in all past ages, is now universally assumed in the speculations of Geology: that they are going on in the present age, we have here endeavored to prove by the evidence of facts. If we have succeeded according to our expectations, the reader will be prepared to admit that, on this point at least, it is not the Geologist who may fairly be charged with having recourse to the inventions of his fancy, but rather those who, assuming as a first principle that Geology is false, perseveringly shut their eyes to the physical changes that are going on around them.
PART II.THE ANTIQUITY OF THE EARTH CONSIDERED IN RELATION TO THE HISTORY OF GENESIS.
The general principles of geological theory accepted by the author—These principles plainly import the extreme antiquity of the earth—Illustration from the coal, the chalk, and the boulder clay—This conclusion not at variance with the inspired history of creation—Chronology of the Bible—Genealogies of Genesis—Date of the creation not fixed by Moses—Progress of opinion on this point—Cardinal Wiseman, Father Perrone, Father Pianciani—Doctor Buckland—Doctor Chalmers, Doctor Pye Smith, Hugh Miller—Author’s view explained—Charge of rashness and irreverence answered—Admonitions of Saint Augustine and Saint Thomas.