he walls
increased, in sympathy with the rise of the roof, while their thickness
remained the same, it became more and more necessary to support them by
buttresses; but--and this is another point that the reader must
specially note--it is not the steep roof mask which requires the
buttress, but the vaulting beneath it; the roof mask being a mere wooden
frame tied together by cross timbers, and in small buildings often put
together on the ground, raised afterwards, and set on the walls like a
hat, bearing vertically upon them; and farther, I believe in most cases
the northern vaulting requires its great array of external buttress, not
so much from any peculiar boldness in its own forms, as from the greater
comparative thinness and height of the walls, and more determined
throwing of the whole weight of the roof on particular points. Now the
connexion of the interior frame-work (or true roof) with the buttress,
at such points, is not visible to the spectators from without; but the
relation of the roof mask to the top of the wall which it protects, or
from which it springs, is perfectly visible; and it is a point of so
great importance in the effect of the building, that it will be well to
make it a subject of distinct consideration in the following Chapter.

FOOTNOTES:

[50] Appendix 17

[51] I do not speak of the true dome, because I have not studied its
construction enough to know at what largeness of scale it begins to
be rather a _tour de force_ than a convenient or natural form of
roof, and because the ordinary spectator's choice among its various
outlines must always be dependent on aesthetic considerations only,
and can in no wise be grounded on any conception of its infinitely
complicated structural principles.

[52] I shall not be thought to have overrated the effect of forest
scenery on the _northern_ mind; but I was glad to hear a Spanish
gentleman, the other day, describing, together with his own, the
regret which the peasants in his neighborhood had testified for the
loss of a noble stone-pine, one of the grandest in Spain, which its
proprietor had suffered to be cut down for small gain. He said that
the mere spot where it had grown was still popularly known as "El
Pino."

[53] Appendix 8.

CHAPTER XIV.

THE ROOF CORNICE.

Sec. I. It will be remembered that in the Sixth Chapter we paused (Sec.
X.) at the point where the additio