Note 20 — Chapter VI

It seems never to have been rightly understood, even by the more intelligent among our architects, that proportion is in any way connected with positive size; it seems to be held among them that a small building may be expanded to a large one merely by proportionally expanding all its parts: and that the harmony will be equally agreeable on whatever scale it be rendered. Now this is true of apparent proportion, but utterly false of constructive; and, as much of the value of architectural proportion is constructive, the error is often productive of the most painful results. It may be best illustrated by observing the conditions of proportion in animals. Many persons have thoughtlessly claimed admiration for the strength—supposed gigantic—of insects and smaller animals; because capable of lifting weights, leaping distances, and surmounting obstacles, of proportion apparently overwhelming. Thus the Formica Herculanea will lift in its mouth, and brandish like a baton, sticks thicker than itself and six times its length, all the while scrambling over crags of about the proportionate height of the Cliffs of Dover, three or four in a minute. There is nothing extraordinary in this, nor any exertion of strength necessarily greater than human, in proportion to the size of the body. For it is evident that if the size and strength of any creature be expanded or diminished in proportion to each other, the distance through which it can leap, the time it can maintain exertion, or any other third term resultant, remains constant; that is, diminish weight of powder and of ball proportionately, and the distance carried is constant or nearly so. Thus, a grasshopper, a man, and a giant 100 feet high, supposing their muscular strength equally proportioned to their size, can or could all leap, not proportionate distance, but the same or nearly the same distance—say, four feet the grasshopper, or forty-eight times his length; six feet the man or his length exactly; ten feet the giant or the tenth of his length. Hence all small animals can, cœteris paribus, perform feats of strength and agility, exactly so much greater than those to be executed by large ones, as the animals themselves are smaller; and to enable an elephant to leap like a grasshopper, he must be endowed with strength a million times greater in proportion to his size. Now the consequence of this general mechanical law is, that as we increase the scale of animals, their means of power, whether muscles of motion or bones of support, must be increased in a more than proportionate degree, or they become utterly unwieldy, and incapable of motion;—and there is a limit to this increase of strength. If the elephant had legs as long as a spider's, no combination of animal matter that could be hide-bound would have strength enough to move them: to support the megatherium, we must have a humerus a foot in diameter, though perhaps not more than two feet long, and that in a vertical position under him, while the gnat can hang on the window frame, and poise himself to sting, in the middle of crooked stilts like threads; stretched out to ten times the breadth of his body on each side. Increase the size of the megatherium a little more, and no phosphate of lime will bear him; he would crush his own legs to powder. (Compare Sir Charles Bell, "Bridgewater Treatise on the Hand," p. 296, and the note.) Hence there is not only a limit to the size of animals, in the conditions of matter, but to their activity also, the largest being always least capable of exertion; and this would be the case to a far greater extent, but that nature beneficently alters her proportions as she increases her scale; giving, as we have seen, long legs and enormous wings to the smaller tribes, and short and thick proportion to the larger. So in vegetables—compare the stalk of an ear of oat, and the trunk of a pine, the mechanical relations being in both the same. So also in waves, of which the large never can be mere exaggerations of the small, but have different slopes and curvatures: so in mountains and all things else, necessarily, and from ordinary mechanical laws. Whence in architecture, according to the scale of the building, its proportions must be altered; and I have no hesitation in calling that unmeaning exaggeration of parts in St. Peter's, of flutings, volutes, friezes, etc., in the proportions of a smaller building, a vulgar blunder, and one that destroys all the majesty that the building ought to have had—and still more I should so call all imitations and adaptations of large buildings on a small scale. The true test of right proportion is that it shall itself inform us of the scale of the building, and be such that even in a drawing it shall instantly induce the conception of the actual size, or size intended. I know not what Fuseli means by that aphorism of his:—