DELTAS IN THE SEA. ons in the Baltic. The question whether the Baltic sea have been sinking, or whether mained stationary, has been a subject of conthe middle of the last century. Celcius, a homer, attempted to prove that the waters 1 suffered a depression at the rate of about es in a century, from the earliest times. He the proof of this change rested not only servations, but also on the authority of the phers, who stated that Scandinavia, now a formerly an island. But most of the arguius and his followers show that they did not tinguish between the shallowing of the water on of sediment, and the actual lowering of pears that the sinking of the waters, on which chiefly made, were at the mouths of rivers, where in the one case inland sediment might nd in the other where loss of depth might by the shifting of sand bars by the current But the facts stated concerning the gradual the Gulf of Bothnia into dry land merit . Thus it was shown that at Pitea, half a ad been gained in forty-five years, and that le of ground had been added in twenty-eight nt ports on the same coast had become inConsiderable portions of the gulf were also e become three feet shallower in the course 's-many old fishing grounds had been dry land, and small islands had been joined at. Besides these changes, it was asserted e coast of West Prussia, and Pomerania, he hulls of old ships, had been discovered was possible that all these facts might be ac7 the accumulation of land, instead of the dehe waters, Celcius derived a stronger aror his theory from the exposure of certain in the gulf of Bothnia, which were once ed by water. These rocks, it was shown, he course of a hundred and fifty years, from tor to the height of eight feet above its cur nd there they stood, the most certain and permaall witnesses, that the sea was so much lower rmerly. To this it was opposed, that this island ed of sand and drift stones, and that during great ts, not only more sand, but additional stones, also, hrown upon it. Besides this, icebergs, heavily laden ones and rocks, sometimes floated in this sea, when was breaking up in the spring, and the fact that v island had gradually increased in height, was readiunted for by supposing that the stranded ice fields had these stones above the level of the water, where of they would remain after the ice was melted away. s question, about which volumes were written in urse of half a century, was finally settled by a cuout conclusive proof, brought forward by the oppoCelcius. On the Finland side of the Baltic, there close to the water's edge, some large pine trees. of these were cut down, and by counting the conrings of annual growth, it was found that they had here four hundred years. Now according to Cele sea had sunk fifteen feet during that period, so ere this the case, these trees must have commenced rowth in at least two fathoms of water, a thing aby impossible. It was also proved that the walls of ancient castles, as those of Sonderburg and Abo, the edge of the water at the present day, and re, had the water sunk, these foundations must have lly been laid below the level of the sea. Very proofs from other sources have also been adduced, e level of the Baltic has suffered no change for undred, or a thousand years. exper geological points, in simple kind. The g ders of the ocean are dim dr several writers, is i e above account there Delta of the Rhone in Rhone deposits large ate of Geneva, and have parency the waters of e the same river towa scarcely has the rive ore its pure waters are by the impetuous Ar and bearing along broken rocks] annual Mount Blanc" The contributions of tran pting, and the prim al France, so that at discolors the waters notwithstanding the proofs are quite positive that pothesis of Celcius can only be substantiated by dearguments, drawn from progressive accumulations matter in the water; still there are many intellien who maintain that the waters of the Baltic are ng a constant diminution. So lately as 1821, seveedish officers, belonging to the pilotage department, ed in favor of this opinion. The weight of eviis, however, entirely opposed to the theory of Celnd there can be little doubt but the Baltic Sea has ed at its present level from time immemorial.-Lyeology, vol. 1. p. 227. have been thus particular in this account, that the leagues. The advance of the de ored by many circum es that an island descr and Latin geographer, which was a harbor shore. It is also kn and in 815, is at the As the Rhone enters derable distances from brought within its infl the land along the shor 6 P ent might observe how much difficulty somedeciding questions of this nature, and conmuch experience and judgment ought to efore any positive opinion is advanced on al points, in themselves apparently of the nd. The great question, also, whether the cean are diminishing, as has been maintainwriters, is involved in the question of the ce this sea communicates with all other seas, › gradual depression would prove a corresution of the sea all over the earth. But from ount there is no doubt, that the supposed Baltic is entirely a deception, arising from ulations brought down by rivers, and the ocg of sand banks by the currents of that sea. e Rhone in the Sea. We have seen that posits large quantities of sediment in the a, and have noticed with what crystalline he waters of that lake are discharged to conriver towards the sea. But, says Mr. Lyhas the river passed out of the Leman Lake, waters are again filled with sand and sedipetuous Arve, descending from the highest ring along in its current the granitic detricks] annually carried down by the glaciers The Rhone, also, afterwards receives ons of transported matter from the Alps of d the primary and volcanic mountains of e, so that when it reaches the Mediterranethe waters of the sea to the distance of ma e of the delta of the Rhone into the Sea, is ny circumstances, and particularly by the land described by Pomponius Mela, an anographer, is now far inland, and that a locas a harbor in 898, is now three miles from is also known that Psamodi, which was an is at the present time six miles from the sea -ne enters the sea by several mouths, at con, nces from each other, a large tract of country hin its influence, and thus besides extending ~ the chara marshos of great extent have the lapse of ages, been filled up by its annual de the course of this river it receives the waters of a umber of springs containing carbonate of lime in soand which mixing with the waters of the Rhone, deposited until it reaches the sea. Hence the Delta river, instead of consisting of loose incoherent sedilike the deposites from most other rivers, consists of solid rock; the carbonate of lime acting as a ceto the sediment, when this exists, or in its absence, g limestone nearly pure. This is a well ascertainfor large masses of this rock are quarried for vapurposes, and are found to consist of sand consolidaa calcareous cement, and mixed with broken shells. he sand has been deposited, the waters still hold a of the carbonate in solution, which is thrown down rer state, and even sometimes in the form of crysAs an example, there exists a cannon in useum of Montpelier, taken up from near the mouth river imbedded in crystalline limestone. masses. s we see that solid limestone is now constantly g, in which are imbedded shells as in the ancient es, which some geologists have contended were nds of years older than the creation according to This circumstance is important, and will be adto in another place. here that the ordinary c der to produce such ef Rise, a strong south-west ally mix the shells of ught down by the fresh Delta of the Po in the ribed the effects whic producing in some Patch it passes. But we changes which this ge, has produced at its These two rivers, with n me of the loftiest ridge h one side of the grea mbined influence of thes late survey of the coast of the Mediterranean, the employed at the mouth of the Rhone were obliged their moorings when the wind blew strongly from uth-west. Captain Smith, one of the officers on rvice, states, that when the ships returned after wind, the new sand banks in the Delta were found 1 with a great abundance of marine shells, which wept there by the current caused by the wind. ircumstance appears to explain phenomena of some ance in geology. In some ancient strata it has aimed that marine and fresh water shells alternate ach other, and hence it has been supposed that at such places, the sea had retired for a time, while water occupied its place; after which the sea again ed its former bed; and so alternately as often as the at kinds of shells were repeated. But it appears he above statement, that the explanation of such ances is very simple, and that it is unnecessary to ous increase of alluvia From the northern here the river Isonzo en ana, there is an uninter postes, forming dry lan length, and from tw There is evidence that thi ithin the last two thousa are name to the Adriati now twenty miles from ere also built on the s st is four, and the las rater. Delta of the Ganges. pter descend from Hir the globe. The latt anch of the former, an mited waters reach the the bay of Bengal, the continent of more th The Delta of the Gra les from the Bay of distance be estimate That part of the Delta ded by a vast number are salt except those w he ordinary course of nature was changed oduce such effects: for, at the mouth of the ng south-west wind only is required, to occahe shells of the sea with those which are by the fresh water, or which live in its cur e Po in the Adriatic. We have already effects which the Po has produced and is ng in some parts of the country through es. But we must notice more particularly which this mighty torrent, assisted by the oduced at its delta in the Adriatic. rivers, with numerous smaller streams, drain loftiest ridges of the Apennines, together of the great Crescent of the Alps. The uence of these rivers have produced an enase of alluvial matter along the coast of that he northernmost point of the gulf of Trieste, er Isonzo enters, down to the south of RaIs an uninterrupted series of recent alluvial ning dry land, more than one hundred miles id from two to twenty miles in breadth. ence that this great alluvion has been formed st two thousand years. Adria, a city which › the Adriatic, was originally a sea-port; it y miles from the sea. Ravenna and Spina ilt on the sea, but, at the present time, the and the last ten or twelve miles from the he Ganges. The Ganges and the Burramd from Himmala mountains, the most lofty The latter river may be considered as a e former, and falls into it long before their 3 reach the sea. The Ganges is discharged of Bengal, which forms a vast indenture into of more than two hundred miles in length. of the Ganges commences more than 200 he Bay of Bengal in a direct line, and 300, if be estimated along the windings of the river. 'the Delta which borders on the sea, is divist number of rivers, or creeks, all of which hich icate with the prin |