County Down in 1837
Climate & Geology
The vicinity of the sea prevents the continuance of frosts on the east and south; and the insulated position of the mountainous tract confines the heavier mists and rains to that part of the county where their effects are least felt. The general inequality of the ground carries off surface waters and prevents damps, so that the climate, although somewhat cold, is considered very wholesome.
The prevailing winds in spring are from the east: westerly winds, although more frequent than from any other point, have not so great a prevalence as in the neighbouring counties. Larch timber thrives on very exposed situations on the Mourne mountains.
The chief geological features are strongly marked. The Mourne and Slieve Croob groups consist of granite. The boundary of this primitive district begins from the east at Dundrum, whence passing northward to Slieve Croob, it runs nearly due west, including the lordship of Newry, and passes into the adjoining counties of Armagh and Louth. This mass of granite reappears in Cavan, and probably is the same which rises on the opposite side of the island in the mountains of Sligo.
Northward and eastward of the granite district the whole of the remainder of the county is occupied by an extension of the transition series which forms the southern basin of Loch Neagh.
Clay slate in greater or less degrees of induration is the prevalent rock. Towards the sea on the north-east and east slate quarries are common.
On the Antrim boundary near Moira an extension of the tertiary limestone formation which occurs throughout the basaltic district occupies a small portion of this county, and affords a most valuable supply of lime manure to the north-western baronies.
Limestone boulders are found along the eastern shore of the Bay of Belfast; and at Carthespil, near Comber, on the western side of Strangford loch, there is a quarry of reddish granular limestone.
Great quantities of marl are raised in the neighbourhood of Downpatrick. The junction of the greywacke and granite may be observed along the eastern branch of the river Lagan, where it rises on Slieve Croob.
Copper ore has been found in the mountains about five miles north-east of Rosstrevor; also near Portaferry, and at Clonligg, between Newtownards and Bangor.
At the latter place is a lead-mine which has been worked with moderate success at various times. Lead ore occurs on the estate of Ballyleady, in the same neighbourhood, and on that of Bryansford. near Newcastle; also at Killough, and near Portaferry.
A lead-mine has likewise been worked in the Blundel estate, half a mile from Dundrum.
Indications of coal have been observed in the north-east of the county, and ochreous earths have been found in various places; but hitherto without leading to any practical result.
Chalybeate spas occur at Newry, Dromore, Magheralin, near Donaghadee and Rathfriland, and at various places in the barony of Ards. A chalybeate strongly impregnated with sulphur and nitre rises about two miles north-west of Ballynahinch, on the declivity of Slieve Croob mountain, which has been found very efficacious in scorbutic cases: the village of Ballynahinch has become a rather fashionable resort during the summer months in consequence.