But the greatest discoveries were due to the workings of the
Commission for the Arterial Drainage and Inland Navigation of Ireland,
which brought no less than twenty-two additional crannogs to light in
the counties of Roscommon, Leitrim, Cavan, and Monaghan. Reports of
these crannogs by the engineers of the Board of Works, with plans,
maps, and sections of the more important (=Figs. 114= and =115=), as
well as the relics collected on them, were given to the Royal Irish
Academy. Unfortunately these relics are now indiscriminately mixed
with other Irish antiquities, and are virtually beyond identification.
Mr. Mulvany, Commissioner of Public Works, makes the following remarks
on the general features of construction of the crannogs encountered by
them during these drainage operations prior to the year 1852:--
[Illustration: =Fig. 114.=--Section of ARDAKILLEN Crannog, near
Strokestown.]
[Illustration: =Fig. 115.=--Plan of Crannog in DRUMALEAGUE LOUGH.
Outer circle 60 feet in diameter.]
"1. They are surrounded by stakes, driven generally in a circle from
60 to 80 feet in diameter; but in some cases the inclosure is larger,
and of an oval shape, as, for instance, that in Loughtown Lake, which
is 120 feet from east to west and 100 feet from north to south;
and one of those in Lough Mac Hugh, which measures 118 feet in one
direction and 74 feet in another.
"2. These outside stakes are generally of oak from 4 to 9 inches in
diameter; sometimes driven in a single row, sometimes double, and in
some cases, as that of island No. 1 in Drumaleague Lake, the stakes
are found in a single row in parts of the island, and in double or
treble rows, or clusters, in other parts. The island in Loughtown
Lake differs from the others in being surrounded by a mass of stakes
upwards of 15 feet wide, and rather inclined towards the centre of the
island.
"3. The portions of the stakes remaining in the ground are evidently
the lower ends of young trees, or of branches of large trees, which
were stuck down just as they grew in the wood; the thicker end
downwards, and bearing the marks of the hatchet by which they were
felled. A considerable length of these stakes must, therefore, have
projected over the ground; and they may probably have been joined
together by horizontal branches, interlaced so as to form a screen,
well calculated to serve for shelter or defence. All the portions of
the stakes which were above ground have been destroyed by time; but
the portions remaining below ground, particularly where the stratum is
pure peat, are generally very sound at heart, and have become as black
as the oak usually found in bogs.
"4. The surface within the staked inclosure is usually covered over
with a layer or two of round logs, cut into lengths of from 4 to 6
feet, over which are found more or less stones, clay, and gravel. In
some cases where the foundation is very soft, as in island No. 2 of
Drumaleague Lake, the layers of timber are very deep. In other cases,
where the ground is naturally firm, the platform of timber is confined
to a portion of the island.
"5. In almost every case a collection of flat stones has been found
near the centre of the inclosure, having marks of fire on them,
and apparently having served as a hearth. In the island No. 2 of
Drumaleague Lake there were three of these hearths found in different
parts of the enclosure.
"6. Considerable quantities of bones are generally found upon or
around the island, being apparently those of deer, black cattle, and
hogs; the skulls of the cows being long and narrow, with very short
horns.
"7. In almost every case one or more pairs of quern stones have been
found within the enclosure.
"8. In many cases pieces of oak-framing have been found, with mortices
and cheeks cut in them. Some of these, such as what were found on
island No. 2 of Drumaleague, appear to have been portions of an
ordinary door-frame; but others, such as those found on the island of
Lough Scur and in Loughtown Lake, are portions of a heavy frame, the
use of which does not appear so evident." (B. 13, Ap., p. 44.)