ROBERT CHAMBERS'S ANCIENT SEA-MARGINS.

Ara one in the slightest degree acquainted with geology is aware of the opinion, received as an axiom, that the earth's surface has been elevated, either by sudden violence or gradual upheaving. Internal commotione -by volcanic agency are assumed to be the violent modus operandi; visible evidence of which is -seen along the range of the Andes and in many other places.; while more inferential proof is found in the breaks and intermixture of strata, and the confusion worse confounded of some mountainous regions. The quieter upheaving of the land cannot be made so palpable to observation as the rapid effects of volcanic eruption, nor is it so -visible in its effects. Some tradition, or accidental mark of olden flues, or continued observation under favourable circumstances, alone furnishes direct evidence; and this is obtainable in several places, espe- daily on the shores of the Baltic. That very high lands have formerly been submerged, is proved by the presence of marine remains, and by appearances which geologists universally admit to bear marks of the action of water. In some cases the regularity both of &trace and of level is so exact, that a violent upheaving seems out of the question. The inference therefore is, that the uprising has been gradual; that the plains and terraces, wearing all the appearance of having formerly been beaches or sea-margins at heights varying from twenty or thirty to a thousand feet above the present level of the ocean, have been gradually raised at different intervals, except in a few instances where it is an unsettled point whether the effects may not have been caused by fresh-water lakes.

From the all but universal opinion of geologists Mr. Chambers dis- sents: he considers that the land has not risen, but that the sea has sunk. This theory or hypothesis has been forced upon him by long ob- servation on a variety of "ancient sea-margins," that appear to him to render his conclusion irrefragable. Having once conceived the idea, he endeavoured to establish it by as extensive a collection of facts as he could meet with in nature or books ; by conferences with geologists, though he appears to have convinced but very few ; and in a paper read last year on the subject before the British Association at Oxford. lie has now expanded that paper in the volume before us ; which pre- sents his general views upon the question, with the evidence by which he supports them. This last consists of observations made by the author in many places throughout Great Britain ; of a rapid survey of the valley of the Seine as high as Paris ; and a casual inspection of parts of Ireland. To these observations are added a variety of measurements from geologi- cal writers relating to America and the North of Europe.

It may be premised, we think, at starting, that the facts of Mr. 'Chambers are hardly-numerous enough, and do not always appear to have been made with a precision sufficiently exact, to establish his premises. With this qualification, the argument may be broadly stated thus. Throughout Great Britain various terraces are found which were evidently salt-water tidal beaches—" ancient sea-margins." They vary in height, from the fiats that in many places border the sea-coasts and the shores of our rivers, up to 1,338 feet above the sea at Ben Lomond. The fact of their existence is well known, and the heights of many of them are ascer- tained as isolated measurements; but if these heights be taken and com- pared together, it will be found that they correspond throughout: if some of the more numerous examples were drawn out, or formed into a model, these differently situated "sea-margins" would exhibit a series of equal tidal lines all round Great Britain. If we proceed to Paris and thence down the valley of the Seine, we find a correspondence in the heights to those which we have already found in Great Britain. In Ireland the re- sult is the same so far as Mr. Chambers has gone. In the North of Eu- rope, especially Norway, the measurements recorded by other geologists exhibit a similar uniformity with those already alluded to. The same correspondence is found in North America.

"I find that a tendency to a bench form or plateau, at 60, or from 60 to 70 feet above present high water, exists on the coasts of the United States and in the Gulf of St. Lawrence, as it does in Britain; that conspicuous terraces in Britain and in France at 188 and 392 feet, are repeated in America; that there also, at about 545 feet, are several repetitions of a decided and most notable Scottish terrace; that Scott built his house of Abbotsford on an ancient sea-beach beside the Tweed, which finds an analogue in the first of the grand ridges sweeping from

• East to West behind Toronto; and that the sandy plateaux of Lanark and Car- stairs are in metrical harmony with the terraces and ridges of the half-peopled wilds of Michigan. Even so high as between 900 and 1,000 feet above the present sea, there is a parity; and we can hardly say anything but a parity, when the fact is that the only two ancient American sea-levels given for that space stand in the following apposition to the Scottish markings within the

Ontario terraces.

Scottish terraces : various districts.

0.

996 996 . . . 999

958-69

937-8

L. 914 907-14

It seems scarcely admissible that accident can have ruled these conformities, ar- rived at by observers in no correspondence with each other. And perhaps even a more perfect uniformity in the Scottish series might have been attained, if avsevere

mode of measurement had been more generally attainable."

From these facts Mr. Chambers deduces the truth of his theory. And it is certainly more easy to conceive a successive falling of the sea-level from the engulfment of a portion of the earth—as, for example, the traditionary Atlantis—than a uniform aeries of uprisings so gradual as to exhibit a perfectly level face, and no breaks in the beaches but what

same space.-

are accounted for by accidents or washings of water. The -subsidence of the ocean is, no doubt, the easiest to our comprehensions, and the most familiar to our experience: the principle is daily illustrated in a cask of beer. Any one could manage it on a model. By having a tap in the bottom of his mimic sea, he could readily enact the hypothetical processes of Mr. Chambers.; whereas only a very complicated machinery could imitate the received opinion of the actual uprising of successive plains or terraces. In nature, however, the uniform levels of these heights would be at once attained by a uniform force acting over a sufficient ex- tent; and we must not limit such large and wonderful operations as were carried on countless ages ago, by our notions of what is the easiest. The volume consists of two portions ; the one exhibiting the writer's general views, and the arguments by which he supports them ; the other embracing a detailed account of his surveys and examinations of different localities in Great Britain, France, and Ireland. The former are broad and interesting : the latter, though necessary as proofs, are rather dry and-detailed, save to a geologist earnest in the question; or interested by the account of the facts apart from the hypothesis ; or possibly acquainted with the places, which always gives zest to a description by recalling the original, and realizing by this process a living idea. In his local sur- veys, however, Mr. Chambers throws in occasional and passing sketches or traditions, which impart WOW lifd to the geologist's "specification." But the general part is the broadest even in its particular facts. The following is curious, though of little proof. Such changes of the sea have taken place within the historic age of this country—at the isle of Sheppey, for example.

"In /819, in digging the earse land at Airthrey near Stirling, where the sur- face is nearly twenty-five feet above high water of spring-tides in the river, which flows at a mile's distance, there were found the bones of a large whale. No doubt can be entertained that this animal had perished here at a time when the sea stood at some unknown point upwards of twenty-five feet above its present level. About five years afterwards, the bones of another large whale were found on the estate of Blair-Drummond, seven miles further up the carse, and probably at a greater ele- vation above the sea. In this case, a deep mass had covered the ground,indi- eating one long section of the interval of time since the death and deposition of the animal. The clay was here only four feet deep, and beneath it was another moss; the memorial, of course, of an interspace, during which dry hind had ex- isted at this spot. The bones rested on the lower moss, but did not penetrate into it. We may suppose, therefore, that it was immediately after the sea re- curred here that the whale was brought to the spot. But the most valuable fact in connexion with these relics is, that in each case there was found among the bones a fragment of stag's-horn, containing a perforation of an inch in diameter, evidently artificial, and, in the Blair-Drummond instance, containing the remains of rotten wood. It was the opinion of Mr. Home Drummond, on whose-property the latter whale was found, that this horn had been the handle of a 'rude in- strument, perhaps a harpoon, and that it had been used in some way in con- nexion with the animal when it was stranded. The purport of these facts and inferences evidently is, that a human population existed in the land before some of the last shifts of the sea-level. I sin moreover told that a human skull was found deeply imbedded in the carse clay at Grangemouth, when digging for the formation of a dock, at a place where recently a garden had flourished. The question must be left, however, to he determined by further evidence."