Geology and Natural History of County Antrim
The most striking features of the surface of this county are its mountains, which stretch in a regular outline from the southern to the northern extremity, terminating on the shore in abrupt and almost perpendicular declivities: they attain their greatest elevation near the coast, and have a gradual descent inland; so that many of the principal streams have their source near the sea, and run directly thence towards Lough Neagh: exclusively of the valleys embosomed amid them, these mountains are computed to occupy about one-third of the superficial area of the county. Between this range and the shore, in some places, are tracts of very fertile land, especially from Belfast to Carrickfergus, and thence to Larne, near which the mountains project in rugged grandeur so as nearly to overhang the sea. From Glenarm round to Bengore Head this succession of rocky headlands presents numerous striking and picturesque views broken by narrow valleys watered by mountain torrents, which give a diversified character to the romantic scenery by which this part of the coast is distinguished.
The most remarkable ranges of cliffs are those of perpendicular basaltic columns, which extend for many miles, and form a coast of surpassing magnificence: their arrangement is most strikingly displayed in Fair Head and the Giant's Causeway, which project several hundred feet into the sea, at the northern extremity of the county. On the western side of the mountain range the valleys expand to a considerable width, and are of great fertility: that of the Six-mile-water, stretching towards the town of Antrim, is particularly distinguished for its beauty and high state of cultivation. The valley of the Lagan merits especial notice for its beautiful undulating surface, its richness, the enlivening aspect of its bleach-greens, and the numerous excellent habitations, with their gardens and plantations, which impart an air of cheerfulness and industry to this interesting vale. The general inclination of the surface of the mountainous region becomes less rapid as it approaches the river Bann: the flattest parts of this elevated tract are composed of turf bogs, which occupy a great space, but are mostly susceptible of improvement. In the southern part of the barony of Toome, along the shore of Lough Neagh to the east of Shane's Castle, the surface consists of numerous detached swells, and presents a remarkably pleasing aspect. Thence southward, along the shore of Lough Neagh to the confines of the county, lies the most extensive level tract within its limits, which for fertility and cultivation is nowhere surpassed.
Detached basaltic eminences, in some instances attaining a mountainous elevation, are conspicuous in several parts of the county, of which Slemish, to the south-east of Broughshane, and 1437 feet high, is the most remarkable: and in divers places, but generally in the lower tracts, are scattered gravelly knolls, which from Antrim to Kells are particularly striking. Off the northern extremity of the county, nearly seven miles distant from the town of Ballycastle, lies the island of Rathlin, about 63 miles in length by 1 ½ in breadth, the shores of which are principally composed of precipitous basaltic and limestone rocks, rearing their heads in sublime grandeur above the waves of a wild and turbulent ocean.
Off this part of the coast are some small islets, and a few others lie off the eastern shore, and in Lough Neagh. Lough Neagh, which is the largest lake in the British islands, is chiefly in this county, but extends into several others:— it is traditionally stated to have been formed in the year 62, by an irruption of the sea, but is obviously formed by the confluence of the Blackwater, Upper Bann, and five other rivers. This lake is about 20 British miles in length from north-east to southwest, about 12 miles in extreme breadth from east to west, 80 miles in circumference, and comprises about 154 square miles: its greatest depth in the middle is 45 feet. According to the Ordnance survey, it is 48 feet above the level of the sea at low water, and contains 98,255 ½ statute acres, of which 50,025 are in this county, 27,355 ½ in Tyrone, 15,556 ¾ in Armagh, 5160 in Londonderry, and 138 in Down.
The only outlet is the Lower Bann, which being obstructed by weirs and rocks prevents the free egress of the waters, and causes the surrounding country to be injuriously inundated in winter. In some places the waters possess medicinal properties, which they are supposed to derive from the adjacent shore. They have also petrifying powers, but these are supposed to exist in the soil, as petrifactions are only found in the lake near the shore of this county, while they are found at considerable heights and depths and at some distance from the coast inland. Valuable hones are made of the petrified wood, and in the white sand on the shore very hard and beautiful stones, known by the name of Lough Neagh pebbles, are found: they are chiefly chalcedony, generally yellow or veined with red, susceptible of a fine polish, and highly valued for seals and necklaces.
Besides the fish usually caught in fresh water lakes, Lough Neagh has the char, a species of trout called the dollaghern, and the pullan or fresh water herring. Swans, teal, widgeon, herons, bitterns, and several other kinds of birds frequent its shores. Canals connect it with Belfast, Newry, and Coal island, and a steam-boat is employed in towing trading vessels across its surface, which, although sometimes violently agitated, is scarcely ever visited by tempests, from the absence of mountains from its borders. This vast expanse of water was frozen in 1739 and 1784, and in 1814 the ice was sufficiently thick for Col. Heyland to ride from Crumlin water foot to Ram's Island, which is the only one of any importance in the lake, and contains the remains of a round tower.
Sir Arthur Chichester, in 1604, received from James I. a grant of the fisheries and of the office of Admiral of Lough Neagh, which have been held by his successors and are now vested in the Marquess of Donegal. Lough Neagh gives the title of Baron to Viscount Masareene. North of this lake, and connected with it by a narrow channel about a mile long, over which is the handsome bridge of Toome, is Lough Beg, or "the small lake," containing 3144 ¾ acres, of which 1624 are in this county, and 1520 ¾ in Derry. This lake, which is generally 15 inches lower than Lough Neagh, contains four small islands, and its banks are more diversified and pleasing than those of the larger lake. The soils are of considerable variety: that of the plains and valleys is a strong loam upon clay, capable of being rendered very fertile, and in many parts interspersed with whinstones lying on or near the surface, the removal of which is necessary preparatory to tillage. On the rising grounds this kind of soil assumes a different quality, the vegetable mould diminishing in quantity, and being lighter in texture and colour; and the substratum deteriorates into a brown or yellow till. Still nearer the mountains this change becomes more apparent from the coarse and scanty produce, rocks and stones in many parts occupying nearly the entire surface, and the soil gradually acquiring a mixture of peat, and thus forming extensive moors.
To the north of the Lagan, at a short distance from Belfast, commences a sandy loam which extends, with occasional interruptions, to the Maze-course, and under good management is very productive: on the shores of Lough Neagh are likewise some tracts of a similar soil: and small stripes of sand are found on different parts of the sea shore. Gravelly soils prevail on the irregularly disposed swells above mentioned, which are composed of water-worn stones of various dimensions, with a loamy covering. There are several detached tracts of soils of various texture, of a superior quality, resting on a substratum of limestone; one of the most extensive lies in the parishes of Maheragall and Soldierstown. Besides the turf, a prevailing soil upon the mountains is a peculiar loam without either cohesion or strength, which appears to be only a rust or oxyde of the softer parts of the ironstone, and under tillage yields exceedingly scanty crops of grain, but, an abundance of straw, and tolerably good crops of potatoes: its herbage forms excellent pasturage.
The main feature in the tillage system of a great part of Antrim is the potatoe fallow, to which it owes nearly as much as Norfolk does to the turnip fallow. The principal wheat district extends along the shore of Lough Neagh and the course of the Lagan river, stretching as far north as Cairdcastle, in approaching which its extent is greatly reduced by the projection of the mountainous districts. Much barley of the four-rowed or Bere species is grown on the dry and gravelly swells; but the cultivation of oats is most extensive, the straw being used as fodder for cattle, and the meal, together with potatoes, the chief food of the great body of the people. The other crops of common cultivation are potatoes and flax: turnips have been grown by some agriculturists since 1774, and the quantity is yearly increasing. In some districts the grass lands are extensive and productive, although a considerable portion formerly employed as grazing pastures is now under tillage: the mountains and high lands also are constantly stocked with either the cattle of the proprietors, or those taken in from distant owners.
Much butter is made throughout the county, and is packed in firkins containing from 60 to 80lb., and sold at Belfast, whence a considerable quantity is exported. Carrickfergus and Antrim have long been celebrated for cheese, some of which rivals in quality that of Cheshire. The principal manure, besides that of the farm-yard, is lime, the produce of the county; but the quarries being situated at its extremities, it requires much labour and expense to convey it into the interior. Near the coast, shells and sea-sand are applied; and sea-sand is also used even where it contains few shells. Great improvement has of late years been made in the agricultural implements, by introducing the best Scotch and English modes of construction. The soil being particularly favourable to the growth of the white thorn, the numerous hedges planted with it greatly enrich the appearance of the lower districts: the mountain fences consist either of loose stones collected from the surface of the ground, or of drains (called shoughs) with banks of earth.
The breed of cattle has been very much improved within the last few years, particularly in the more fertile districts; the most esteemed English and Scottish breeds have been introduced, and by judicious crosses stock of the most valuable kind are becoming general. In several parts is a Bengal breed, imported by Sir Fras. McNaghten, Bart., from which several crosses have been tried, but they appear too tender to endure the cold of winter. Generally, little attention is paid to the improvement of the breed of sheep, though on the rich lands of Muckamore and Massareene it has been very much improved: the old native sheep are principally found in and near the barony of Carey. A very hardy and strong, though small, race of horses, partly bred in the county and partly imported from Scotland, is employed on the northern and north-eastern coast, and among the mountains; and in Rathlin island is a breed similar to these, but still smaller. In other parts of the county the horses are of a good size and valuable kinds, but are chiefly introduced by dealers from other counties. The long-legged flat-sided hogs formerly reared have been superseded by the best English breeds: the bacon and pork of more than 100,000 are annually exported from Belfast.
There is but little natural wood in the county, the greater portion being that which surrounds Shane's Castle, and the scattered trees on the steep banks of a few rivers. Numerous, and in some instances extensive, plantations have, however, been made in various parts; and, though there are still many wide naked tracts, there are others well clothed with wood, especially adjoining Lough Neagh, the vicinities of Moneyglass and Drumraymond, the valleys of the Six-mile-water, Kellswater, and the Braid, the whole extent from Lisburn to Carrickfergus, the neighbourhood of Bella hill and Castle Dobbs, of Larne, Glenarm, Benvarden, O'Hara-brook, Ballynacre, Leslie hill, and Lisanoure. The greatest tracts of waste land are the highest portions of the mountain range: even the irreclaimable bogs of these elevated tracts produce a coarse herbage, and many of the bogs which overspread to a considerable extent the plains between the mountains and the Bann are likewise covered with verdure. Towards the southern part of the county most of the bogs have been exhausted.
Coal is furnished to the northern and eastern coasts from the mines of Ballycastle, but the chief supply is from England, Wales, and Scotland. The geology of Antrim presents a great variety of the most interesting features, and its mineral productions are of considerable importance. With the exception of a diversified district on the eastern coast and the entire vale of the Lagan, nearly the whole is occupied by basaltic beds, presenting abrupt declivities on the eastern and northern coasts, which are truly magnificent. These secondary beds consist of enormous unstratified masses, the average depth of which is about 300 feet, though in the north, at Knock-laid, it is 980 feet; the base of that mountain is composed of mica slate.
The island of Rathlin is principally occupied by these basaltic beds, which are classified by Dr. Berger under the following heads: — tabular basalt, columnar basalt, green-stone, grey-stone, porphyry, bole or red ochre, wacke, amygdaloidal wacke, and wood coal: and imbedded in them are granular olivine augite, calcareous spar, steatite, zeolite, iron pyrites, glassy feldspar, and chalcedony. The beds of columnar basalt occur almost exclusively towards the northern extremity of the county, and form an amazing display of natural grandeur along the shore. Besides the well-known columnar strata composing the Giant's Causeway and the adjacent cliffs, similar strata are seen in divers parts of the county, particularly near Antrim and Kilroot: the pillars composing the Giant's Causeway (which is minutely described in the article on Billy), are irregular prisms standing in the closest contact, and of various forms, from three to nine sides, the hexagonal equalling in number all the rest. Slievemish, or Slemish, mountain is an enormous mass of greenstone, which likewise occurs in other situations.
Porphyry occupies a considerable district to the south of Connor and Kells, and is met with in several other places, particularly near Cushendall. The remarkable substance called wood coal occurs in thin strata at Portnoffer, Kiltymorris, Ballintoy, and elsewhere. All the other rocks of Antrim are beneath the basaltic beds in geological position. The first is hard chalk, sometimes called white limestone, which does not average more than 200 feet in thickness, and occurs on the eastern and southern sides of the county, and on the southern coast of Rathlin island. Mulattoe, or green sandstone next occurs in the neighbourhood of Belfast, to the north of Carrickfergus, near Larne, at Garron Point, &c.; and under this are found lias beds on the coast between Garron Point and Larne, and in other places. These, together with the chalk and basalt, are based upon beds of reddish and reddish-brown sandstone of various textures, which are found under the entire south-eastern border of the county, in several detached spots along the eastern coast, and in considerable tracts from Red bay to Ballycastle: the upper strata form a marl, in which are veins of gypsum.
The coal district of Ballycastle comprises an extent of about two miles along the coast; the beds crop out above the level of the sea, dipping to the south-east about one foot in nine, and alternate with others of sandstone and slate clay, being themselves of a slaty quality. The only rocks lying under the strata of the great coal district, besides the primitive rocks of mica-slate, &c., already mentioned, are those of "old red sandstone," between the bays of Cushendall and Cushendun. All the above-mentioned strata are occasionally intersected and dislocated by remarkable dykes of basalt or whinstone, varying from three inches to sixteen feet in width. Sometimes very minute dykes or veins of greenstone penetrate these enormous beds of basalt, and are particularly observable near Portrush, where they are seen in the face of the cliff not more than an inch broad. Chert is also found in abundance and variety at Portrush.
Fullers' earth exists in the basaltic district, in which also a rough tripoli is found at Agnew's Hill, and a vein of steatite or French chalk in the path to the Gobbins. In Belfast Lough, lying under the level of the ordinary tides, but generally left bare at the ebb, is a stratum of submarine peat and timber, in which nuts are singularly petrified on the east and west sides of the Lough. Numerous organic remains are also found in the beds of chalk, &c.; large and beautiful crystals in the basaltic region, particularly near the Giant's Causeway, where agates, opal, and chalcedony are met with in different situations. Of all this variety of subterranean productions, the coal has been procured to the greatest extent. The collieries of Ballycastle, once flourishing, are now but little worked; they were formerly twelve in number, and exported from 10,000 to 15,000 tons annually. Gypsum or alabaster is dug in different places, and the various species of stone are quarried in spots convenient for building and other purposes.