thickness has
been cut off next the choir. A portion of the triforium wall, a
piece of the string-course over the main arcade, and the corbelled
vaulting shaft in the angle as high as the top of the triforium, are
also parts of the original structure. The later work has been joined
to the above old parts in a very awkward manner."[392] The cap of
the west pier on the north side belongs to the first pointed work,
while the corresponding cap on the south side and all the other caps
belong to the fifteenth century restoration.[393] Except the west
piers, the piers of the nave are of the clustered form, common in
late Scottish work, and might be about the same date as the
restoration of St. Giles, Edinburgh (which they resemble), in the
early part of the fifteenth century.[394]

The triforium design consists of large segmental arches, the same
width as the main arches, springing from short clustered piers
introduced between them. It somewhat resembles the triforium of the
nave at Dunkeld Cathedral. The clerestory is probably designed in
imitation of that of Glasgow Cathedral, and is divided into two
pointed arches in each bay. They spring from a series of clustered
shafts with round moulded caps that are late imitations of early
work.[395] The earlier part of the nave restoration, including the
main piers and arches, and perhaps the tracery of the two lower
windows of the west front, were possibly executed by Bishop Lithgow,
who built the north porch, and the completion of the nave (the upper
portions) was carried out in the time of Abbot Tervas--the middle of
the fifteenth century. A peculiarity of the nave interior is a
series of large corbels, which project from the spandrils of the
triforium arcade, and the object of which was to enable a passage to
be carried round the solid piers introduced between the windows.
Each of the large corbels springs at its lowest point from the
sculptured grotesque figure of a man or animal. They were mostly the
work of Thomas Hector, a sculptor, who lived at Crossflat,[396] and
whom the abbot retained for his skill in the art.[397] The
employment of such grotesque figures was very much affected by the
monks of Clugny, and was the occasion of a rebuke from St. Bernard.
"What business had these devils and monstrosities in Christian
churches, taking