uildings; a comparison of the ruin with the
Irish oratories; notices of other Island Retreats of Saints, and of the
Saints themselves. In one of these he gives an instructive reference to
a passage in the original Latin text of Boece about the round tower of
Brechin, which had been overlooked by his translator Bellenden, and so
was now quoted for the first time.

A copy of this paper on Inchcolm having been sent to his friend Dr.
Petrie of Dublin, author of the well-known essay on the "Early
Ecclesiastical Architecture and Round Towers of Ireland," it was
returned after a time, enriched with many notes and illustrations. In
now reprinting the paper these have been added, and are distinguished
from the author's notes by having the letter P annexed to them. The
subject of the Inchcolm oratory was one about which this great man felt
much interest, and on which he could speak from the abundance of his
knowledge and experience. The notes are therefore of special value, as
furnishing the latest views of the author on mooted points of Celtic
Ecclesiology, while they are conspicuous for the modesty and candour
which were combined with Dr. Petrie's vast learning on the subject.

Thus, in his work on the Round Towers, Dr. Petrie assigned "about the
year 1020" as the date of the round tower of Brechin, but in one of the
notes he corrects himself, and explains the origin of his mistake:--"The
recollection of the error which I made, by a carelessness not in such
matters usual with me, in assigning this date 1020, instead of between
the years 971 and 994, as I ought to have done, has long given me
annoyance, and a lesson never to trust to memory in dates; for it was
thus I fell into the mistake. I had the year 1020 on my mind, which is
the year assigned by Pinkerton for the writing of the _Chron. Pictorum_,
and, without stopping to remember or to refer, I took it for granted
that it was the year of Kenneth's death, or rather of his gift."

In writing of the Early Churches or Oratories of Ireland, Dr. Petrie
stated in his Essay--"they had a single doorway always placed in the
centre of the west wall." In one of his notes, now printed, he thus
qualifies the statement:--"I should perhaps have written _almost_
always. The very few exceptions did not at the moment occur to me."
Again, Sir James Simpson having quoted a passage from Dr. Petrie's work,
in which the writer ascribes the old small stone-roofed church at
Killaloe to the sevent