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Show 230 .SUPPOSED DlMJNUTION OF of the sea in the year 1000 ; and after eight centuries, its relative position remains exact~y ~he same*· Notwithstanding these convu~cmg proofs that the supposed change in the relative level of land and sea arose from some l~cal appcar.a nc es , there are still many who cot:ttefn dh for . a lowermg of the Baltic ; and many Swedish officers o t e pi1 ? tage. e.sta-bl. h t declared in the year 18!ill, in favour of this opm1on, Is men ' d · h · 1 a f ter measur·m g t11e- height of landmarks place. at certam eig. 1ts a b ove th e sea, half a Cent·u ry before' as ob. Jects .o f companson for the express purpose of settling the. pomt at. Issue. Before we attach any wei~Yht to these assertions, which only relate 1. 1 t d' ~r ces 0 to s 1g 1 weren of elevation ' we oug.h t to be as·s ured· thbal t t 11 e ob servers Wel·e on their guard agm.n st every Imagma e f deceptl.on arising from local circumstances. Thus, cause o . · 1 d · 1.J' 0r examp1 e , 1' f t]1e )1eicnr ht of an alluvial plam was ta {CD . urmg the last century, it might have been subsequently raised by fresh deposits, and thus the sea would appear to have sunk ; or, if a mark was cut in the rocks, the se~ may have been several inches or even feet higher at one perwd than an~ther, in consequence of the setting in of a ?urrent ur~ed by partiCulat· winds into a long narrow gulf, winch cause Is wel~ kno':n to raise the Baltic, at some seasons, two feet above Its ordmat'Y level. . d Udd Von Duch, in his travels,discovered·m· Norwa~, an at . ~- 11 · Sweden beds of shells of existing species at consider-va a, m ' · 1 · able heights above the level of the water: Smce ~ 1at time, several other naturalists have confirmed his observ~tiOn; anc~, according to Strom, some deposits occur at an elevatiOn of mme than four hundred feet above the sea in the nort~l~rn part of N M Alex Brongniart who has lately vJsited U dde-orway. · · ' 1 · · £ valla in Gotheborg, a port at the entrance of the Ba tic, m orms us that the principal mass of shells in the creek of U ddev~lla . bout two hundred feet above the level of the sea, restmg rises. ac k, of gneiss. All the species are I'd enti·C a1 W·l th those n.o w on 10 o · £ h t art entire, inhabiting the contiguous sea, and are or t e mos P b ·I although some of them are broken, as happens on a ~ea- e::e;· They are nearly free from any admixture of ear~ ! ~a f ~ The reader need scarcely be reminded that, at the eig o fi our readers to Von • For a full account of the Celsian controversy, we may re er Hoff, Geschichte, &c., vol. i,, P· 439. THE LEVEL OF THE BALTIC. 231 few feet above the beach, on our coasts, the rocks, where they are alternately submerged and laid dry by the ebbing and flowing tide, are frequently covered with barnacles or balani, which are :firmly attached. On examining, with care, the smooth surface of the gneiss, immediately above the ancient shelly beach at Uddevalla, M. Brongniart found, in a similar manner, balani adhering to the rocks, so that there can be no doubt that the sea had for a long period sojourned on the spot*. Now, this interesting fact is precisely analogous to one well known to all who are acquainted with the geology of the borders of the Mediterranean. Perforating shells (Venus lithophaga, Lam.) excavate funnel-shaped hollows in the hardest limestone and marble, along the present sea-shores; and lines of these perforations, sometimes containing the same species of shells, have been discovered at various heights above the sea near Naples, in Calabria, at Monte Pelegrino, in the Bay of Palermo, and other localities. As many of these districts have been violently shaken by earthquakes within the historical era, and as the land has been sometimes raised and sometimes depressed, as we shall afterwards show by examples, there is no difficulty iu explaining the phenomena, provided time be allowed. But no argument can be det·ived, from such observations, in support of great upheavings of the coast, whether by slow or sudden operations in modern times, unless we use the term modern in a geological sense. On the contrary, we know that the physical outline of the coast and heights in the bay of Palermo, when it was a Greek port more than two thousand years ago, was so nearly the same as it i~ at present, that the beds of recent shells, and the perforations 1n the rocks, must have stood nearly in the same relation to the level of the Mediterranean as they stand now. The high beaches on the Norwegian and Swedish coast establish the important and certainly very unexpected fact, that those parts of Europe have been the theatres of considerable subterranean move~ents. within the present zoological era, or since the seas were mhabtted by species now our contemporaries. But the pheno~ena do not lend the slightest support to the Celsian hy~ othests, nor to that extraordinary notion proposed in our own times by Von Buch, who imagines that the whole of the land •, * Tableau des Terrains, &c., p. 89. 1829. |