elliptical, to be made less weak; or that an arch,
which, by its elliptical form, is superiour in strength to the
semicircle, may become almost as strong as a semicircle, by being made
almost semicircular.

That the longer diameter of an ellipsis may be shortened, till it shall
differ little from a circle, is indisputably true; but why should the
writer forget the semicircle differs as little from such an ellipsis? It
seems that the difference, whether small or great, is to the advantage
of the semicircle; for he does not promise that the elliptical arch,
with all the convexity that his imagination can confer, will stand
without cramps of iron, and melted lead, and large stones, and a very
thick arch; assistances which the semicircle does not require, and which
can be yet less required by a semi-ellipsis, which is, in all respects,
superiour in strength.

Of a man who loves opposition so well, as to be thus at variance with
himself, little doubt can be made of his contrariety to others; nor do I
think myself entitled to complain of disregard from one, with whom the
performances of antiquity have so little weight; yet, in defiance of all
this contemptuous superiority, I must again venture to declare, that a
straight line will bear no weight; being convinced, that not even the
science of Vasari can make that form strong which the laws of nature
have condemned to weakness. By the position, that a straight line will
bear nothing, is meant, that it receives no strength from straightness;
for that many bodies, laid in straight lines, will support weight by the
cohesion of their parts, every one has found, who has seen dishes on a
shelf, or a thief upon the gallows. It is not denied, that stones may be
so crushed together by enormous pressure on each side, that a heavy mass
may safely be laid upon them; but the strength must be derived merely
from the lateral resistance; and the line, so loaded, will be itself
part of the load.

The semi-elliptical arch has one recommendation yet unexamined: we are
told, that it is difficult of execution. Why difficulty should be chosen
for its own sake, I am not able to discover; but it must not be
forgotten, that, as the convexity is increased, the difficulty is
lessened; and I know not well, whether this writer, who appears equally
ambitious of difficulty, and studious of strength, will wish to increase
the convexity for the gain of strength, or to lessen it for the love of
difficulty.