NORTH SEA (Germanieum Mare; Ger. Nord See), that arm of the Atlantic ocean which separates the British islands on the w. from the continent on the cast. It is 700 in. in extreme length (from n. to s.), about 400 m, in greatest breadth, and has an area of not less than 140.000 sq. miles The great commercial highwaysfrom the North sea to the Atlantic are by the Pentland firth and the strait of Dover: while on the e. it communicates with the Baltic by the Skagerrack, the Cattegat, Sound, and Great and Little Belts. Along its south-eastern and southern coasts the shores are low, and are skirted by sand banks, formed by the sand deposits carried to the sea by the waters of the Elbe, Weser, Rhine and Scheldt, which are the principal rivers that flow into the sea from the east. The shores of England, especially in the s., are also low, and here sand has also accu mulated, though not nearly to the same extent as on the continental coasts. The chief British rivers that fall into the North sea are the Thames, Ouse, Humber, Tyne, Tweed, Forth, and Tay. Besides the sand-banks on the coast already referred to, there arc others extending to the middle of the sea-bed, and similar in their origin to those on the coasts, and occupying altogether about three-fourths of the entire area. Of these, the principal are the bank running me. from the mouth of the firth of Forth for 110 m. ; the one extending ti.w. from the mouth of the Elbe for about the seine distance; the Dogger bank (q.v.), etc. These sand-banks, combined with the storms and fogs so common in the North sea, render its navigation unusually dangerous. Another peculiarity of the bed of this sea is, inc number of extraordinary holes" which have been found in it. Of these the most remarkable are the Little Silver Pitt off Holderness in Yorkshire, and the North-north-east Hole, 8 leagues further east. Little Silver Pitt is 25 in. in length. and from half a mile to 2 m. in width. At its edges there is a depth from 50 to 80 ft. of
water, but the •' hole" has a depth of 330 feet. In the n., along the Norwegian coasts, the sbores are steep and rocky, and there is a depth of about 190 fathoms. The depth (31 fathoms on an average) increases from s. to north. The currents of this ocean are extremely various, and demand the greatest caution on the part of the navigator. Owing to the prevalence of s.w. winds, the currents show a general tendency towards the north-east. On the south-western coast of Ireland, the great tidal wave of the Atlantic is broken into two portions, one of which, coursing up the, channel, passes through the strait of Dover; while the other, sweeping n., passes round the n. of Scotland. and then south-ward along the e. coast of Britain, and meets the southern wave off the coast of Essex. The northern portion of the tidal wave spreads over the whole of the German ocean, and though on its entrance into the North sea it is only 12 ft. in height, it rises in its progress southward, as the sea becomes narrower. in the same way as the bore (q.v.) is formed in a contracting estuary. In the estuary of the Humber it rises to the height of 20 feet. This sea yields immense quantities of fish, the most important kinds being cod, hake, ling, turbot. sole, mackerel and herring, also lobsters. The fisheries employ many thousand people. On all available points of the coasts, light-houses have been erected, and there are numerous floating-light vessels moored to detached banks. The traffic on the" North sea is enormous. It is surrounded by countries whose inhabitants have from the earliest times been famous on the seas, and the enterprise and national bias that formerly covered the Scandinavian waters with conquering fleets, may now be traced in the vast commercial intercourse carried on on the North sea.