But instead of viewing a rank of uniform pillars, let us suppose that they succeed each other, a round and a square one alternately.

In this case the vibration caused by the first round pillar perishes as soon as it is formed; and one of quite another sort (the square) directly occupies its place; which however it resigns as quickly to the round one; and thus the eye proceeds, alternately, taking up one image, and laying down another, as long as the building continues.

From whence it is obvious that, at the last pillar, the impression is as far from continuing as it was at the very first; because, in fact, the sensory can receive no distinct impression but from the last; and it can never of itself resume a dissimilar impression: besides every variation of the object is a rest and relaxation to the organs of sight; and these reliefs prevent that powerful emotion so necessary to produce the sublime.

To produce therefore a perfect grandeur in such things as we have been mentioning, there should be a perfect simplicity, an absolute uniformity in disposition, shape, and coloring.

Upon this principle of succession and uniformity it may be asked, why a long bare wall should not be a more sublime object than a colonnade; since the succession is no way interrupted; since the eye meets no check; since nothing more uniform can be conceived?
A long bare wall is certainly not so grand an object as a colonnade of the same length and height.