TOPOGRAPHY. The• seas surrounding Great Britain are very shallow, rarely exceeding 300 feet in depth. The fact that the island stands on the Continental shelf has two great advantages: (1) It is protected from the cold waters of the deep Arctic currents, and thus is spared the chill ing influences of the Northern Ocean. (2) The shallow surrounding waters are fitted in tempera ture and in abundant supplies of fish food to sup port myriads of the best varieties of fish, so that the fisheries constitute one of the great indus tries, the enormous population finding in them the only home source of food whose product is in adequate supply.
The coasts are extremely long in proportion to the area of the land. Europe, with a much longer coast-line in proportion to area than any other continent, has one mile of coast to every 200 miles of area; but Great Britain has one mile of coast to less than 20 miles of area, the shore-line, particularly on the west side, being broken up into a series of bold headlands and deep bays penetrating far into the land, so that England has a coast-line nearly 2000 miles in length, while that of Scotland is considerably longer. No part of the island is more than 70 miles from the coast. The broken character of the coasts is determined, of course, by the nature of the rocks. The headlands are formed of the harder rocks which are worn away very slowly by the sea waves and other agencies of coastal destruction. The numerous indentations and deep bays are found where the softer rocks have been worn away by the action of water and other disintegrating agencies. Two causes have con tributed to increase the value of these indenta tions as harbors. One is the subsidence or depression of the entire western side of the island, so that the sea has been able more deeply to invade the valleys (drowned valleys) ; the other is the rise of the tides all around the coasts, from 6 to 30 feet (the latter height at Bristol), which converts the mouths and lower parts of many rivers into deep bays or channels. Without the tide, London could never have become a great seaport. The deep-sea lochs of the west coasts of Scotland are similar in appearance and origin to the fiords of Norway. Here, as on the western coast of England, all the softer rocks have been washed away; and on the Scottish coast there is left an outer barrier of islands and an inner wall of very hard rocks penetrated by these deep fiords. On the other
hand, the east coast of•Scotland, composed mainly of sandstone and clay, has been easily worn into deep estuaries at the mouths of rapid rivers like the Tay; and the east side of England, composed of soft rocks, has been worn into a low, monoto nous line of shore, broken only by the estuaries of rivers whose current is too sluggish to wear away deep channels. Most of the good harbors are, therefore, along the west and south shores of the island. The south coast is picturesque, with lofty cliffs and rocky shores dotted with summer resorts.
The highlands and lowlands of Great Britain may roughly be divided into four well-defined areas: (1) The Scottish Highlands, a mountain ous and comparatively barren region, lie north west of a line drawn from Dumbarton to Aber deen. (2) The Scottish Lowlands, an expanse of fertile lowland and the Southern Uplands, lie southeast of this line. (3) The mountains of England and Wales lie northwest of a line drawn from Exeter to Berwick. (4) The lowlands of England lie to the southeast of this line.
There are in the Scottish Highlands a number of parallel ranges of mountains, the highest mountain being Ben Nevis, 4406 feet, the cul minating point of the island. The only pas sageways are at their extremities. At these ex tremities are the two roadways through Scot land from south to north, the eastern coast forming the easiest and most traveled route, its importance being increased by the fertile plains which the eastward draining streams have multi plied in Scotland on the borders of the North Sea. These plains have a large population. Plains are lacking on the Atlantic seaboard where the mountains descend to the sea. The crystalline rocks of the Highlands yield only a meagre soil, and the difficulties of production are increased by the high northern latitude, giving a raw climate and the excessive precipitation which results in very numerous peat-bogs and tarns that con siderably diminish the available surface. On the other hand, the abundant alluvium of the eastern plains makes a fertile soil, and wheat is grown as far north as Moray Firth in latitude 58°. The. seaboard, however, is the main source of pros perity, facing, as it does, Europe, sheltered from the west winds, and supplied with a group of fine ports. Trade and the fisheries absorb the energies of the larger part of the population of this section.