Lewis Topographical Dictionary - OSi Online Shop

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wellan; and the entire county is well wooded. The oak
every where flourishes vigorously; in the parks and
demesnes of the nohility and gentry there is a great
quantity of full-grown timber, and extensive plantations
are numerous in almost every part, particularly in the
vale of the Lagan, from Belfast to Lisburn, and around
Hollywood, and many of the hills have been successfully
planted.
The Mourne mountains, extending from Dundrum
bay to Carlingford bay, form a well-defined group, of
which Slieve Donard is the summit, being, according to
the Ordnance survey, 2796 feet above the level of the
sea, and visible, in clear weather, from the mountains
near Dublin: granite is its prevailing constituent. To
the north of these’ mountains, Slieve Croob, composed
of sienite, and Slieve Anisky, of hornblende, both in
Lower Iveagh, constitute an elevated tract dependent
upon, though at some distance from, the main group.
Hornblende and primitive greenstone are abundant on
the skirts of the granitic district. Mica slate has been
noticed only in one instance. Exterior chains of tran-
sition rocks advance far to the west and north of this
primitive tract, extending westward across Monaghan
into Cavan, and on the north-east to the southern cape
of Belfast Lough, and the peninsula of Ardes. The
primitive nucleus bears but a very small proportion, in
surface, to these exterior chains, which are principally
occupied by grauwacke and grauwacke slate. In the
Mourne Mountains and the adjoining districts an exten
sive formation of granite occurs, but without the varieties
found in Wieklow, agreeing in character rather with the
newer granite of the Wernerians: it constitutes nearly
the whole mass of the Mourne mountains, whence it
passes across Carlingford bay into the county of Louth.
On the north-west of these mountains, where they slope
gradually into the plain, the same rock reaches Rath-
friland, a table land of inconsiderable elevation. Within
the boundaries now assigned, the granite is spread over
a surface of 324 square miles, comprehending the highest
ground in the North of Ireland. Among the accidental
ingredients of this formation are crystallised hornblende,
chiefly abounding in the porphyritic variety, and small
reddish garnets in the granular: both varieties occur
mingled together on the top of Slieve Donard. Water-
worn pebbles, of porphyritic sienite, occasionally con-
taining red crystals of feldspar and iron pyrites, are very
frequent at the base of the Mourne mountains, between
Rosstrevor and Newcastle: they have probably been
derived from the disintegration of neighbouring masses
of that rock, since, on the shore at Glassdrummin, a
ledge of porphyritic sienite, evidently connected with
the granitic mass of the adjoining mountain, projects
into the sea. Greenstone slate rests against the accli-
vities of the Mourne mountains, but the strata never
rise high, seldom exceeding 500 feet. Attempts have
been made to quarry it for roofing, which it is thought
would be successful if carried on with spirit. Feldspar
porphyry occurs in the bed of the Finish, north-west of
Slieve Croob, near Dromara, and in a decomposing state
at Ballyroany, north-east of Rathfriland, Slieve Croob
seems formed, on its north-east and south-east sides, of
different varieties of sienite, some of them porphyritic
and very beautiful: this rock crops out at intervals
from Bakaderry to the top- of Slieve Croob, occupying
an elevation of about 900 feet. Grauwacke and grau-
VOL. I—489
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wacke slate constitute a great part of the baronies of
Ardes, Castlereagh, and the two Iveaghs: it is worked
for roofing at Ballyalwood, in the Ardes; and a variety
of better quality still remains undisturbed at Cairn
Garva, south-west of Conbigg Hill. Lead and copper
ores have been found in this formation at Conbigg Hill,
between Newtown-Ardes and Bangor, where a mine is
now profitably and extensively worked. Two small
limestone districts occur, one near Downpatrick on the
south-west, and the other near Comber on the north
west, of Strangford Lough. The old red sandstone has
been observed on the sides of Strangford Lough, parti-
cularly at Scrabo, which rises 483 feet above the lough,
and is capped with greenstone about 150 feet thick; the
remaining 330 feet are principally sandstone, which may
be observed in the white quarry in distinct beds of very
variable thickness, alternating with grauwacke. This
formation has been bored to the depth of 500 feet on
the eastern side of Strangford Lough, in the fruitless
search for coal, which depth, added to the ascertained
height above ground, gives from 800 to 900 feet as its
thickness. The greatest length of this sandstone dis-
trict is not more than seven miles; it appears to rest on
grauwacke. Coal, in three seams, is found on the shores
of Strangford, and two thin seams are found under the
lands of Wilnmount, on the banks of the Lagan; there
are also indications of coal in two places near Moira.
Chalk appears at Magheralin, near Moira, proceeding
thence towards the White mountains near Lisburn, and
forming a low table land. The quarries chiefly worked
for freestone are those of Scrabo and Kilwarlin, near
Moira, from the latter of which flags are raised of great
size and of different colours, from a clear stone-colour
to a brownish red. Slates are quarried on the Ardes
shore, between Bangor and Ballywalter, and near Hills-
borough, Anahilt, and Ballinahinch: though inferior to
those imported from Wales in lightness and colour, they
exceed them in hardness and durability. In the lime-
stone quarries near Moira, the stone is found lying in
horizontal strata intermixed with flints, in some places
stratified, and in others in detached pieces of various
forms and sizes: it is common to see three of these large
flints, like rollers, a yard long and twelve inches each in
diameter, standing perpendicularly over each other, and
joined by a narrow neck of limestone, funnel-shaped, as
if they had been poured when in a liquid state into a
cavity made to receive them. Shells of various kinds
are also found in this stone.
The staple manufacture is that of linens, which has
prevailed since the time of Wm. III., when legislative
measures were enacted to substitute it for the woollen
manufacture. Its establishment here is owing greatly
to the settlement of a colony of French refugees, whom
the revocation of the edict of Nantes had driven from
their native country, and more especially to the exertions
of one of them, named Crommelin, who, after having
travelled through a considerable part of Ireland, to
ascertain the fitness of the country for the manufacture,
settled in Lisburn, where he established the damask
manufacture, which has thriven there ever since. The
branches now carried on are fine linen, cambrics, sheet-
ings, drills, damasks, and every other description of
household linen. Much of the wrought article, par-
ticularly the finer fabrics, is sent to Belfast and Lurgan
for sale; the principal markets within the county are
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