d are carried up, without break or buttress, to the
parapet, where they are finished with a gable roof, forming the
saddle-back arrangement still preserved in the Muthill Tower.[14] The
break in the height is formed by string courses, which mark the unequal
stories. A small wheel-stair usually leads to the top, and the doorway
is occasionally several feet from the ground. Such are the leading
features that can be traced in the buildings connected with the period.

2. SCOTTISH TRANSITION STYLE

The term "transition" is by general agreement reserved for the
architecture of the end of the twelfth century, when the Norman style
gradually gave place to the first pointed Gothic style. In England this
period extends from about 1180 to 1200; in Scotland it extends
considerably into the thirteenth century. The characteristics of the
style are the gradual introduction of the pointed arch and its use
along with some of the decorative features of the Norman style. "The
pointed arch shows the advent of the new style, but the ornaments of the
old style continue to linger for a time. The first pointed style was not
complete till these old ornaments were abandoned, and the more vigorous
enrichments of the new style were introduced. The other constructive
features of the Norman style gradually changed at the same time as the
arch. The buttresses by degrees assumed the projecting form of the first
pointed style, and the pinnacles and spires of the latter style were in
course of time introduced."[15]

3. SCOTTISH FIRST POINTED PERIOD

"The pointed Gothic style which had its origin in the north of France
about the middle of the twelfth century appeared in England about 1170,
but can scarcely be said to have reached Scotland till after the close
of the twelfth century.... The pointed arch, for example, although
generally adopted, did not entirely displace, as it had done in the
south, the round form of the Normans, a feature which, especially in
doorways, continued to be employed not only in the thirteenth century,
but throughout the whole course of Gothic art in Scotland. In other
respects the thirteenth century style in this country corresponds very
closely with that of England. Its features are however, generally
speaking, plainer and the structures are smaller."[16]

"This new departure sprung from the necessity which arose for the
invention of an elastic system of vaulting which should admit of all the
arches, forming vaults o