IRELAND, the most westerly and smaller of the two principal islands of which the United Kingdom of Great Britain and Ireland is com posed, extends from lat. 51° 26' to 55° 21' N. and long. 5° 25' to 10° 30' W.; its greatest length is 302 miles; greatest breadth, 174 miles; area, 32,583 square miles. It is separated from England by Saint George's Channel and the Irish Sea, and from Scotland by a narrow passage, the North Channel. Ireland is on the continental shelf, or submarine plain, which borders the continental land mass of Europe, hence it is physically part of Europe.
The coast line is irregular ; from Dundalk Bay to Wexford Harbor on the cast there are less indentations than on any other part of the coast; Dublin Bay, an arm of the Irish Sea, is the only indentation of any size on this part of the island. Galway, Sligo and Donegal bays are the largest on the western coast. The Atlantic currents, which beat against the western coast, have worn away the land in many places, thus causing fiords such as exist on the coasts of other countries subject to similar wave-action. Some of the many islands which fringe the coast have been formed by the washing away or the submergence of the land. The capes, promontories, and peninsulas have been formed largely by submergence. Some of the islands, all small, are Aran, Achill, Clare, and Rathlin. The chief ports are Cork, Dublin, Belfast, Waterford, Londonderry and the arti ficial harbor of Rosslare. There are 14 harbors which will accommodate the largest ocean steamers.
The highlands are chiefly along the coast; the greater part of the interior is a plain. The mountains, more rounded hills than mountains, are short ranges with little or no connection ex cept the several ranges in the southwest. Some of the mountains are Mourne, in County Down, the Wicklow Mountains, Knockmealdown and Galty in the south; Caha, Stack and other ranges in Kerry; Slieve Boughta in Galway, a num bet Of 'short ranges in the counties 'of Mayo, Leitrim, Donegal and Londonderry, and the Slieve Bloom between Queens and Kings coun ties. The majority of the peaks are less than
3,000 feet in height; Carrantuohill (Carrantual), in Kerry, near the Lakes of Killarney, is 3,414 feet, and Galty Mountains, in Limerick, are 3,015 feet. The plain in the interior is about 500 feet above sea-level.
Hydrography.— The rivers of Ireland, like those of England and Scotland, are small streams. The Shannon, the largest river in the British Isles, has its rise in the northeastern part •of the province of Connaught, flows east, south, and west, forming quite a curve before entering the Atlantic Ocean, between the counties of Kerry and Clare. It passes through several lakes, the largest of which are Ree, Allen and Derg. The estuary at the mouth is about 70 miles long; the whole length of the river is about 250 mites, 130 of which are navigable for large steamers. Its importance for transporta tion has been increased by the canals Royal and Grand, which connect it with Dublin. In the southwest, in County Kerry, is a short mountain stream called Roughly River, with a long, broad estuary called Kenmare River. The Liffey, which flows into the Irish Sea at Dublin, the Lee which flows into Cork Harbor, the Boyne with its tributary, the Blackwater, are all short streams which have been made famous in his tory and literature. The Foyle, Erne, Lagan, Moy, Slaney, and others reach the ocean through broad estuaries or bays. Lough Neagh (183 square miles) in the northwest is the largest lake of the British Isles. A number of the lakes of Ireland occur along the river courses, but are really basins, and not merely expan sions of the rivers. Lakes Conn, Foyle, Bel fast, Strangford, Carlingford, and others on the coast are estuaries or fiords, but the land-locked mouths entitle them to be called lakes, like Maracaibo in South America. The famous Lakes of Killarney are in County Kerry, in the southwestern part of the island. There is scarcely a place in Ireland that is more than 25 miles distant from water communication with the ocean.