GENERAL KNOWLEDGE

centre—(1) They are very prolific, being covered with the particular kinds of sea-weed amongst which the fish find their food and lay their eggs. (2) The sea is so small—only about twice as large as the British Isles—that the fishermen have not to go very far from their homes. (3) For the same reason, markets arc very near. One of the’markets, Billingsgate, supplies London—the largest city in the world. The North Sea never freezes, even up the coast of Norway This is due to the Gulf Stream and the warm south-west winds, which keep the coast-line of Europe free from ice even within the Arctic circle. The Baltic Sea is only three-auarters the size of the North Sea, and is landlocked, so that it has no perceptible tide. It is also so shallow that it has very few good harbours. The only really Sound—the good one is Copenhagen, which stands on the shortest and the straightest of the three channels into the Baltic from the Kattegat. The Scand in avian Mountains to the west of it intercept all the warm wet south-west winds, but send down into it a very large number of rivers and the huge plain of Ru ia to the east of it exposes; it to the cold, dry, north-east winds from Siberia. The Baltic is more or le ice-bound for four months in the year, during which mails and pa engers are sometimes sent acro in sledges. Even in Riga, which is in the latitude of Dundee, the harbour has been blocked for nearly three months in the year with a line of icebergs more than thirty feet high, and nearly a mile long. The Mediterranean presents some strong contrasts to the Baltic Sea, in size, depth, drainage, latitude, and water. It is six times as large, and at least one hundred times as deep. Between Malta and Crete it is about as deep as the Matter horn mountain is high, whereas the Baltic is very seldom more than fifty feet. Like the Baltic, it is too small and too much landlocked to have a real tide but, while the Baltic has a current out through the; Kattegat, the Mediterranean has a current in through the Straits of Gibraltar and while the Baltic is very fresh, the Mediterranean; is very salt. The reasons for this current in are— (1) The sea gets comparatively little fresh water from rivers. (2) It loses a great deal by the rapid evaporation in such a southern latitude. In the old days, under the Tyrians and Cart hag in i ans, the Greeks and the Romans, the Mediterranean was the great centre of trade in the known world but its prosperity —(1) disappeared for three centuries owing; to The Turkish invasion of Europe from the east. (2) The diversion of trade westward to America, and round the Cape of Good Hope to the east. Improvements in ocean, opposed to sea, navigation. (3) Since the opening of the Suez Canal in 1869, the old prosperity has returned. The Black Sea is nearly as large as the Baltic, and its average depth is nearly as great as that Of the Mediterranean. Like the Baltic, it receives a very large amount of river water but, like the Mediterranean, it is in a southern latitude.; Consequently it is more salt than the Baltic, but le salt than the Mediterranean. Its great depth keeps its water very cold; and the huge plains round it expose it to great extremes of temperature, and especially to dry, hot winds in summer. Consequently, like the great lakes of Canada, it is subject to sudden storms and dense fogs. The Caspian Sea is about the same size as the Black Sea, but it has no outlet at all. Consequently, ajl its surplus water has to be got rid of by evaporation, and this causes it’to be extremely salt. It is also being gradually filled up by the mud brought down by the Volga, as the Sea of Azov is by the mud brought down by the Don. It is nearly 7000 miles smaller than it was 100 years ago, and this is affecting both its climate and its commercial value. It is probably, like the Sea of Aral, a remnant of a huge sea which connected the Black Sea with the Arctic Ocean, and which separated Europe from Asia. Sight (in Gaelic Taisch) was formerly quite common, but the world is too prosaic and matter-of fact now to contain many souls pure enough and exalted enough in mind to be endowed with that power ot seeing future or distant events as if they