PRACTICAL GEOLOGY &C. IN IRELAND.
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by a comparison of the round towers with early Anglo-Norman castles, is illustrated by a sectional drawing of the circular keep at Pembroke, of which
Round Tower Crypt of St Kevin.
Mr. Wilkinson has given, for the first time, as we believe, a detailed representation. In reference to this structure, he makes the following observations.
"Its security, too, so much like that afforded by the round towers, was owing to its small circumference, erected for the reception of a warrior chief, the lord of the castle and his family. The space obtained is but limited, but protection, the chief object of the erection, is, as in the round tower, admirably obtained; for the staircase ascending in the wall, which was thick enough to admit it, would render the approach to the upper rooms, even if the entrance door was passed, to be a matter of difficulty, and would place a limited party of defenders on equal terms with a powerful body of assailants, whose only approach could be that of the narrow passage; and in those days when artillery was slumbering, they were free from all danger except that of famine, until released by succour, or the retreat of their assailants; for their stone-built castle was proof against, doubtless, the most powerful agent in those times, viz., fire; and if even floor after floor was demolished, they would only advance still higher—and fearful would be the destruction they would cause to the assailants from the elevated and advantageous position the defenders would occupy, where, by gravity alone, stones would become more powerful weapons than any which could be brought against them by their assailants, from the reach of whose arms they would be almost free." P. 89.
In pursuing the notice of the architectural peculiarities of the ancient structures of Ireland, we can only afford space to allude to those which are the most prominent, and in contrast to such as are common in our own
