BALTIC, or EASTERN SEA, next to the Medi terranean, the most important of the inland seas of Europe. Though it does not appear the Bal tic was ever visited by the Romans, it is mentioned under various names' by several of their writers, as a place, of whose existence, at least, they were perfect ly aware. It is the Venedicus Sinus of Ptolemy ; the Mare Suevicum of Tacitus ; and, the Sinus Codanus of Pliny. In the countries which hound it, its an cient name was Variatzkoie More, or the sea of Va riaglii. The modern Russians call it Baltiskoe MorC, and the Swedes, Oster Sjow.
The Baltic opens from the German sea between the 57° and 59° N. Lat. by a gulf pointing north east, and is there called the Skager Rack ; it next passes several degrees south in what is called the Cattegat, to. the south -east of which is the sound of Elsineur, a nar row streight between the coast of Sweden and the island of Zealand. This is the general passage for ships going from the North Sea into the Baltic ; and a small toll is here paid by wayofcourtesy to the crown of Denmark, which, in return, erects light-houses, and keeps them in proper repair. After passing Zealand, this sea' spreads widely to the north-east, and is at last branch ed out into the two extensive gulfs of Bothnia and Finland ; the former of which stretches north as far as Torneo, within a few degrees of the Arctic circle ; the latter extends in a direction almost due east, till it comes within a short distance of the lake Ladoga. Both these gulfs are either covered or much impeded with ice during four or five months of the year. His tory informs us, indeed, that even the whole of the sea has been, at various times, completely frozen over. In the year 1333, travellers passed on the ice from Lubec to Prussia and Denmark, and tents were erected at certain intervals for their accommodation. The same phenomenon occurred in the years 1399, 1423, 1459, and 1533 ; in 1709, and 1740, the frosts were also remarkably severe, though the ice was by no means so eneral or so strong as in the other instan ces mentioned. These facts serve, with many others, to confirm a favourite theory of modern naturalists, that the rigour of the seasons in the northern corm tries of Europe, was 'formerly much greater than at present. • The length of the Baltic from south-west to north east, is more than 600 miles : it is in general about 75 miles broad, but in some places it spreads to the breadth of ILO miles. Its depth does not exceed fifty
fathoms, and it is said to subside at the rate of 45 inches in a century. Mr Otto, however, in his phy sical observations on the Baltic Sea, has suggested another theory, which is at least plausible, to account for its apparent decrease. He supposes, that instead of really subsiding, it may only be slightly shifting its position, and gaining in one quarter as much as it loses in another. This effect he ascribes to the large rivers, which flowing into this sea with great rapidity, carry with them vast quantities of earth and sand, by which the beds at their mouths are raised, and their banks extended towards the sea. The waves of the Baltic do not swell so high as in the ocean, but they are more dangerous and harassing to the ship ping, as they succeed each other with greater rapidity and impetuosity. Amber is deposited in its agita tions on the shores of Courland and Prussia and it appears, that all the knowledge which the Romans possessed of the maritime powers of the Baltic, was obtained by their merchants, who journeyed by land in search of amber. Its water does not contain above one-thirtieth part of salt, whereas the water of other seas often holds one-tenth. This freshness may pro ceed in part from the number of large rivers which discharge themselves into this sea ; but it seems to be chiefly owing to the large quantities of ice formed in its northern gulfs. It has a very perceptible current ; and when the wind blows strong from the north, the water becomes so fresh as to be even fit for drinking or preparing meat. Even in the hottest summers the Baltic is cooler than any other sea. Though it has no regular tides, being almost entirely surround ed by land, yet when a strong west wind prevails for any considerable time, its natural outlet is pre vented, and a large accession of water is forced into it from the North Sea ; on such occasions, it rises on its coasts a little above its ordinary level. The eb bing and flowing of the German Ocean, though very• weak, is said to co-operate with the Baltic, so that traces of their effects may be perceived.