Volume 3 - Electric Scotland

ORIGIN OF THE ARCH. 1^35
easy to imagine two straight inclined stones meeting, with
squared terminations, it is equally so to suppose that they
had been fitted by a perpendicular joint. In either case
the structure is sufiicient for its purposes. In either case
also it is easy to conceive that taste had given a curva-
ture to the stones ; and thus the graceful form of the
arch becomes combined with its utility. Such is, even at
present, an arch of this character where its dimensions are
not too considerable ; it is little changed from its original
germ, and that germ is found in the two inclined stones
which form the doorway of our Pictish or subterranean
vaults. But if that mode of forming an arch, or the sub-
stitute for one, is the most simple and obvious, it appears
also to possess an actual historical claim to the highest
antiquity. It forms the entrance to the Pyramid of
Cheops, it occurs in the walls of the Greek Thebes, in
the ancient Cyclopean remains of Italy, and in some sub-
terraneous vaultings in that country, of unknown, and
probably of Etruscan antiquity. That it is found, as I
lately showed, in the chapels of Barra, serves no purpose
but to indicate how poverty or want of dexterity has re-
trograded to the same primitive form.
Thus the inclined stones form a species of Gothic arch,
though a rude one ;
and in the cases quoted, the angle is
acute. This arch is also necessarily of small dimensions,
because it must thus have been determined by the length
of a single stone. Increasing in size, it required two
stones on each side, remaining equally efficacious, if, as is
here presumed, a sense of beauty had led the artists to
give the whole a curvature. In the rudest case, where
all the joints, even that at the summit, were naturally
made perpendicular to the tangent of the curvature at
the point where they occurred, the perfect meeting of
the archi volts, or the perpendicular joint, was still want-