he shores of
Inchcolm. The hermit's cell or oratory is placed on perhaps the most
protected spot on the island; and yet it would have been scarcely
habitable with an open window exposing its interior to the east, and
with a door placed directly opposite it in the western gable. It has
been rendered, however, much more fit for a human abode by the door
being situated in the south wall; and the more so, because the ledge of
rock against which the south-west corner of the building abuts, protects
in a great degree this south door from the direct effects of the western
storm. The building itself is narrower than the generality of the Irish
oratories, but this was perhaps necessitated by another circumstance,
for its breadth was probably determined by the immovable basaltic blocks
lying on either side of it.

The head of the doorway in the Inchcolm oratory is, as pointed out in a
preceding page, peculiar in this respect, that externally it is
constructed on the principle of the radiating arch, whilst internally it
is built on the principle of the horizontal arch. But in other early
Irish ecclesiastical buildings in Scotland, as well as in Ireland, the
external and internal aspect of the doorway is sometimes thus
constructed on opposite principles. In the round tower, for example, of
Abernethy, the head of the doorway externally is formed of a large
single stone laid horizontally, and having a semicircular opening cut
out of the lower side of the horizontal block; while the head of the
doorway internally is constructed of separate stones on the plan of the
radiating arch.

One striking circumstance in the Inchcolm oratory--viz., its vaulted or
arched roof, has been already sufficiently described; and, in describing
it, I have stated that the arch is of a pointed form. In many of the
ancient Irish oratories the roof was of wood, and covered with rushes or
shingles; and most of them had their walls even constructed of wood or
oak, as the term _duir-theach_ originally signifies. But apparently,
though the generic name duir-theach still continued to be applied to
them, some of them were constructed, from a very early period, entirely
of stone; and of these the roofs were occasionally formed of the same
material as the walls, and arched or vaulted, as in the Inchcolm
oratory. In speaking of the construction of the primitive larger
churches of Ireland, Dr. Petrie states, that their "roof appears to have
been constructed generally