The wall of Antonine, therefore, yields no evidence in favour of the land having remained stationary since the time of the Romans, but on the contrary, appears to indicate that since its erection the land has actually risen. Recent explorations by Mr. Geikie and Dr. Young, of the sites of the old Roman harbours along the southern margin of the Firth of Forth, lead to similar inferences. In the first place, it has long been known that there is a raised beach containing marine sh.e.l.ls of living littoral species, at a height of about 25 feet, at Leith, as well as at other places along the coast above and below Edinburgh. Inveresk, a few miles below that city, is the site of an ancient Roman port, and if we suppose the sea at high water to have washed the foot of the heights on which the town stood, the tide would have ascended far up the valley of the Esk, and would have made the mouth of that river a safe and commodious harbour; whereas, had it been a shoaling estuary, as at present, it is difficult to see how the Romans should have made choice of it as a port.

At Cramond, at the mouth of the river Almond, above Edinburgh, was Alaterva, the chief Roman harbour on the southern coast of the Forth, where numerous coins, urns, sculptured stones and the remnant of a harbour have been detected. The old Roman quays built along what must then have been the sea margin, have been found on what is now dry land, and although some silt carried down in suspension by the waters of the Forth may account for a part of the gain of low land, we yet require an upward movement of about 20 feet to explain the growth of the dreary expanse of mud now stretching along the sh.o.r.e and extending outwards, where it attains its greatest breadth, well-nigh two miles, across which vessels, even of light burden, can now only venture at full tide. Had these shoals existed eighteen centuries ago, they would have prevented the Romans from selecting this as their chief port; whereas, if the land were now to sink 20 feet, Cramond would unquestionably be the best natural harbour along the whole of the south side of the Forth.*

(* Geikie, "Edinburgh New Philosophical Journal" for July 1861.)

Corresponding in level with the raised beach at Leith, above mentioned (or about 25 feet above high-water mark), is the Ca.r.s.e of Stirling, a low tract of land consisting of loamy and peaty beds, in which several skeletons of whales of large size have been found. One of these was dug up at Airthrie,* near Stirling, about a mile from the river, and 7 miles from the sea.

(* Bald, "Edinburgh Philosophical Journal" 1 page 393 and "Memoirs of the Wernerian Society" 3 page 327.)

Mr. Bald mentions that near it were found two pieces of stag's horn, artificially cut, through one of which a hole, about an inch in diameter, had been perforated. Another whale, 85 feet long, was found at Dunmore, a few miles below Stirling,* which, like that of Airthrie, lay about 20 feet above high-water mark.

(* "Edinburgh Philosophical Journal" 11 pages 220, 415.)

Three other skeletons of whales were found at Blair Drummond, between the years 1819 and 1824, 7 miles up the estuary above Stirling,* also at an elevation of between 20 and 30 feet above the sea. Near two of these whales, pointed instruments of deer's horn were found, one of which retained part of a wooden handle, probably preserved by having been enclosed in peat. This weapon is now in the museum at Edinburgh.

(* "Memoirs of the Wernerian Society" volume 5 page 440.)

The position of these fossil whales and bone implements, and still more of an iron anchor found in the Ca.r.s.e of Falkirk, below Stirling, shows that the upheaval by which the raised beach of Leith was laid dry extended far westward probably as far as the Clyde, where, as we have seen, marine strata containing buried canoes rise to a similar height above the sea.

The same upward movement which reached simultaneously east and west from sea to sea was also felt as far north as the estuary of the Tay. This may be inferred from the Celtic name of Inch being attached to many hillocks, which rise above the general level of the alluvial plains, implying that these eminences were once surrounded by water or marshy ground. At various localities also in the silt of the Ca.r.s.e of Gowrie iron implements have been found.

The raised beach, also containing a great number of marine sh.e.l.ls of recent species, traced up to a height of 14 feet above the sea by Mr.

W.J. Hamilton at Elie, on the southern coast of Fife, is doubtless another effect of the same extensive upheaval.*

(* "Proceedings of the Geological Society" volume 2 1833 page 280.)

A similar movement would also account for some changes which antiquaries have recorded much farther south, on the borders of the Solway Firth; though in this case, as in that of the estuary of the Forth, the conversion of sea into land has always been referred to the silting up of estuaries, and not to upheaval. Thus Horsley insists on the difficulty of explaining the position of certain Roman stations, on the Solway, the Forth, and the Clyde, without a.s.suming that the sea has been excluded from certain areas which it formerly occupied.*

(* "Britannia" page 157 1860.)

On a review of the whole evidence, geological and archaeological, afforded by the Scottish coast-line, we may conclude that the last upheaval of 25 feet took place not only since the first human population settled in the island; but long after metallic implements had come into use, and there seems even a strong presumption in favour of the opinion that the date of the elevation may have been subsequent to the Roman occupation.

But the 25 feet rise is only the last stage of a long antecedent process of elevation, for examples of Recent marine sh.e.l.ls have been observed 40 feet and upwards above the sea in Ayrshire. At one of these localities, Mr. Smith of Jordanhill informs me that a rude ornament made of cannel coal has been found on the coast in the parish of Dundonald, lying 50 feet above the sea-level, on the surface of the boulder-clay or till, and covered with gravel containing marine sh.e.l.ls. If we suppose the upward movement to have been uniform in central Scotland before and after the Roman era, and a.s.sume that as 25 feet indicate seventeen centuries, so 50 feet imply a lapse of twice that number, or 3400 years, we should then carry back the date of the ornament in question to fifteen centuries before our era, or to the days of Pharaoh, and the period usually a.s.signed to the exodus of the Israelites from Egypt. [8]

But all such estimates must be considered, in the present state of science, as tentative and conjectural, since the rate of movement of the land may not have been uniform, and its direction not always upwards, and there may have been long stationary periods, one of which of more than usual duration seems indicated by the 50-foot raised beach, which has been traced for vast distances along the western coast of Scotland.

COAST OF CORNWALL.

Sir H. De la Beche has adduced several proofs of changes of level, in the course of the human period, in his "Report on the Geology of Cornwall and Devon," 1839. He mentions (page 406) that several human skulls and works of art, buried in an estuary deposit, were found in mining gravel for tin at Pentuan, near St. Austell, the skulls lying at the depth of 40 feet from the surface, and others at Carnon at the depth of 53 feet. The overlying strata were marine, containing sea-sh.e.l.ls of living species, and bones of whales, besides the remains of several living species of mammalia.

Other examples of works of art, such as stone hatchets, canoes, and ships, buried in ancient river-beds in England, and in peat and sh.e.l.l-marl, I have mentioned in my work before cited.

SWEDEN AND NORWAY.

In the same work I have shown that near Stockholm, in Sweden, there occur, at slight elevations above the sea-level, horizontal beds of sand, loam, and marl, containing the same peculiar a.s.semblage of testacea which now live in the brackish waters of the Baltic. Mingled with these, at different depths, have been detected various works of art implying a rude state of civilization, and some vessels built before the introduction of iron, and even the remains of an ancient hut, the marine strata containing it, which had been formed during a previous depression, having been upraised, so that the upper beds are now 60 feet higher than the surface of the Baltic. In the neighbourhood of these recent strata, both to the north-west and south of Stockholm, other deposits similar in mineral composition occur, which ascend to greater heights, in which precisely the same a.s.semblage of fossil sh.e.l.ls is met with, but without any intermixture, so far as is yet known, of human bones or fabricated articles.

On the opposite or western coast of Sweden, at Uddevalla, Post-Tertiary strata, containing recent sh.e.l.ls, not of that brackish water character peculiar to the Baltic, but such as now live in the Northern Ocean, ascend to the height of 200 feet; and beds of clay and sand of the same age attain elevations of 300 and even 600 feet in Norway, where they have been usually described as "raised beaches." They are, however, thick deposits of submarine origin, spreading far and wide, and filling valleys in the granite and gneiss, just as the Tertiary formations, in different parts of Europe, cover or fill depressions in the older rocks.

Although the fossil fauna characterising these upraised sands and clays consists exclusively of existing northern species of testacea, it is more than probable that they may not all belong to that division of the Pleistocene strata which we are now considering. If the contemporary mammalia were known, they would, in all likelihood, be found to be referable, at least in part, to extinct species; for, according to Loven (an able living naturalist of Norway), the species do not const.i.tute such an a.s.semblage as now inhabits corresponding lat.i.tudes in the North Sea. On the contrary, they decidedly represent a more arctic fauna. In order to find the same species flourishing in equal abundance, or in many cases to find them at all, we must go northwards to higher lat.i.tudes than Uddevalla in Sweden, or even nearer the pole than Central Norway.

Judging by the uniformity of climate now prevailing from century to century, and the insensible rate of variation in the geographical distribution of organic beings in our own times, we may presume that an extremely lengthened period was required even for so slight a modification in the range of the molluscous fauna, as that of which the evidence is here brought to light. There are also other independent reasons for suspecting that the antiquity of these deposits may be indefinitely great as compared to the historical period. I allude to their present elevation above the sea, some of them rising, in Norway, to the height of 600 feet or more. The upward movement now in progress in parts of Norway and Sweden extends, as I have elsewhere shown,*

throughout an area about 1000 miles north and south, and for an unknown distance east and west, the amount of elevation always increasing as we proceed towards the North Cape, where it is said to equal 5 feet in a century.

(* "Principles" 9th edition chapter 30.)

If we could a.s.sume that there had been an average of 2 1/2 feet in each hundred years for the last fifty centuries, this would give an elevation of 125 feet in that period. In other words, it would follow that the sh.o.r.es, and a considerable area of the former bed of the North Sea, had been uplifted vertically to that amount, and converted into land in the course of the last 5000 years. A mean rate of continuous vertical elevation of 2 1/2 feet in a century would, I conceive, be a high average; yet, even if this be a.s.sumed, it would require 24,000 years for parts of the sea-coast of Norway, where the Pleistocene marine strata occur, to attain the height of 600 feet. [9]

CHAPTER 4. -- PLEISTOCENE PERIOD--BONES OF MAN AND EXTINCT MAMMALIA IN BELGIAN CAVERNS.

Earliest Discoveries in Caves of Languedoc of Human Remains with Bones of extinct Mammalia.

Researches in 1833 of Dr. Schmerling in the Liege Caverns.

Scattered Portions of Human Skeletons a.s.sociated with Bones of Elephant and Rhinoceros.

Distribution and probable Mode of Introduction of the Bones.

Implements of Flint and Bone.

Schmerling's Conclusions as to the Antiquity of Man ignored.

Present State of the Belgian Caves.

Human Bones recently found in Cave of Engihoul.

Engulfed Rivers.

Stalagmitic Crust.

Antiquity of the Human Remains in Belgium how proved.

Having hitherto considered those formations in which both the fossil sh.e.l.ls and the mammalia are of living species, we may now turn our attention to those of older date, in which the sh.e.l.ls being all recent, some of the accompanying mammalia are extinct, or belong to species not known to have lived within the times of history or tradition.

DISCOVERIES OF MM. TOURNAL AND CHRISTOL IN 1828 IN THE SOUTH OF FRANCE.

In the "Principles of Geology," when treating of the fossil remains found in alluvium and the mud of caverns, I gave an account in 1832 of the investigations made by MM. Tournal and Christol in the South of France.*

(* 1st edition volume 2 chapter 14 1832, and 9th edition page 738, 1853.)

M. Tournal stated in his memoir that in the cavern of Bize, in the department of the Aude, he had found human bones and teeth, together with fragments of rude pottery, in the same mud and breccia cemented by stalagmite in which land-sh.e.l.ls of living species were embedded, and the bones of mammalia, some of extinct, others of recent species. The human bones were declared by his fellow-labourer, M. Marcel de Serres, to be in the same chemical condition as those of the accompanying quadrupeds.*

(* "Annales des Sciences Naturelles" tome 15 1828 page 348.)

Speaking of these fossils of the Bize cavern five years later, M.

Tournal observed that they could not be referred, as some suggested, to a "diluvial catastrophe," for they evidently had not been washed in suddenly by a transient flood, but must have been introduced gradually, together with the enveloping mud and pebbles, at successive periods.*

(* "Annales de Chimie et de Physique" 1833 page 161.)

M. Christol, who was engaged at the same time in similar researches in another part of Languedoc, published an account of them a year later, in which he described some human bones, as occurring in the cavern of Pondres, near Nimes, in the same mud with the bones of an extinct hyaena and rhinoceros.*

(* Christol, "Notice sur les Oss.e.m.e.nts humains des Cavernes du Gard" Montpellier 1829.)

The cavern was in this instance filled up to the roof with mud and gravel, in which fragments of two kinds of pottery were detected, the lowest and rudest near the bottom of the cave, below the level of the extinct mammalia.