DOWN, a maritime county of Ireland, occupying the most easterly part of the island, bounded north by Co. Antrim and Belfast Lough, east and south by the Irish sea, and west by Co. Armagh. The area is 6o8,86i acres. Pop. (1926), 209,228.
The foundation of this county is Silurian rock throughout, the slates and sandstones striking as a whole north-east, but giving rise to a country of abundant small hills. The granite that appears along the same axis in Armagh continues from Newry to Slieve Croob, furnishing an excellent building stone. South of it, the Eocene granite of the Mournes forms a group of rocky summits, set with scarps and tors, and divided by valleys, which are not yet choked by the detritus of these comparatively youthful mountains (Slieve Donard 2,796 ft.). Lower lands occupy the east, north and large portions of the west of the county. Basalt dykes abound, being well seen along the coast south of Newcastle. At the head of Strangford Lough, the basalt, possibly as intrusive sheets, has protected Triassic sandstone, which is quarried at Scrabo hill. A strip of marine Permian occurs on the shore at Holywood. The north-west of the county includes, at Moira, a part of the great basaltic plateaux, with Chalk and Trias protected by them. The chief drainage is to the river Lagan in the north, and to the Bann and the Newry on the west. The period at which Down was constituted a county is not certain. A district, how ever, appears to have borne this name before the beginning of the i4th century, but little is known of it even later than this. However, when in Sir John Perrot undertook the shiring of Ulster, Down and Antrim were excepted as already settled coun ties. That some such settlement would have been attempted at an early period is likely, as this coast was a place of Anglo-Norman colonization, and to this movement was due the settlement of the baronies of Lecale, the Ards and others.
At Slidderyford, near Dundrum, there is a group of ten or twelve pillar stones in a circle, about i o ft. in height. A cairn on the summit of Slieve Croob is 8o yds. in circumference at the base and 5o at the top, where is a platform on which cairns of various heights are found standing. Cromlechs, or altars, are numerous, the most remarkable being the Giant's Ring, which stands on the summit of a hill near the borders of Antrim. This altar is in the centre of an enclosure about a third of a mile in circumference, formed of a rampart about 20 ft. high, and broad enough on the top to permit two persons to ride abreast. Near Downpatrick is a rath, or encampment, three-quarters of a mile in circumference. In its vicinity are the ruins of Saul Abbey, said to have been founded by St. Patrick, and Inch Abbey, founded by Sir John de Courcy in 1180. The number of monastic ruins is also considerable. The most ancient and celebrated is the abbey or cathedral of Downpatrick. Dundrum Castle, at tributed to the de Courcy family, stands above that town, and affords an unusual example (for Ireland) of a donjon keep. The castle of Hillsborough, seat of the marquesses of Downshire, is of Carolean date. There are three round towers in the county, but all are fragmentary.
The predominating soil is a loam of little depth, in most places intermixed with considerable quantities of stones of various sizes, but differing materially in character according to the nature of the subsoil. Clay is mostly confined to the eastern coast, and to the northern parts of Castlereagh. Of sandy soil the quantity is small; it occurs chiefly near Dundrum. Moor grounds are mostly confined to the skirts of the mountains. Bogs, though frequent, are scarcely sufficient to furnish a supply of fuel to the population. Agriculture is in a fairly satisfactory condition. The bulk of the labouring population dwells in reasonably good cir cumstances. Tillage land declines somewhat in favour of pasture land. Oats, potatoes and turnips are the principal crops ; flax, formerly important, is almost neglected. Some of the best race horses in Ireland have been bred in this county. The native breed of sheep is confined to the mountains. The various other kinds of sheep have been much improved. Pigs are reared in great numbers, chiefly for the Belfast market. Poultry farming is a growing industry. The fisheries, of less value than formerly, are centred at Donaghadee, Newcastle, Strangford and Ardglass. The chief industries in the county generally are linen manufac ture and bleaching, and brewing.
The haematite of Deehommed,near Banbridge, is well spoken of. Topaz and aquamarine occur in hollows in the granite of the Mournes. The Mourne granite is quarried above Annalong, and an ornamental dolerite is worked at Rosstrevor.
The Great Northern railway has an alternative branch to its main line by Portadown, from Lisburn through Banbridge to Scarva, with a branch from Banbridge to Ballyroney and New castle. Newry is on a branch from the Dublin-Belfast line to Warrenpoint on Carlingford Lough. The main line between Lis burn and Portadown touches the north-western extremity of the county. The eastern part of the county is served by the Belfast and County Down railway with its main line from Bel fast to Newcastle, and branches from Belfast to Bangor, Comber to Newtownards and Donaghadee, Ballynahinch Junction to Bal lynahinch, and Downpatrick to Ardglass and Killough. The Newry Canal skirts the west of the county, and the Lagan Canal intersects the rich lands in the Lagan valley to the north.
Newry (Pop. about I2,o00) is the largest town, Downpatrick is styled the county town. Other towns include Banbridge and Bangor, and there are popular watering-places on the coast and residential villages on Belfast Lough. Co. Down returns eight members to the parliament of Northern Ireland and two members to the parliament of Great Britain and Northern Ireland.