To the sublime in building, greatness of dimension seems requisite; for
on a few parts, and those small, the imagination cannot rise to any idea
of infinity. No greatness in the manner can effectually compensate for
the want of proper dimensions. There is no danger of drawing men into
extravagant designs by this rule; it carries its own caution along with
it. Because too great a length in buildings destroys the purpose of
greatness, which it was intended to promote; the perspective will lessen
it in height as it gains in length, and will bring it at last to a
point; turning the whole figure into a sort of triangle, the poorest in
its effect of almost any figure that can be presented to the eye. I have
ever observed, that colonnades and avenues of trees of a moderate length
were, without comparison, far grander than when they were suffered to
run to immense distances. A true artist should put a generous deceit on
the spectators, and effect the noblest designs by easy methods. Designs
that are vast only by their dimensions, are always the sign of a common
and low imagination. No work of art can be great, but as it deceives; to
be otherwise is the prerogative of nature only. A good eye will fix the
medium betwixt an excessive length or height (for the same objection
lies against both), and a short or broken quantity: and perhaps it might
be ascertained to a tolerable degree of exactness, if it was my purpose
to descend far into the particulars of any art.