Michael Angelo went alone a way unknown before him, and (strange to tell!) untrod since the time of that genius of modern sculpture.
This Phidias of latter times, and next to the Greeks, hath, in all probability, hit the very mark of his great masters. We know at least no method so eminently proper for expressing on the block every, even the minutest, beauty of the model.
Vasari[13] seems to give but a defective description of this method, viz. Michael Angelo took a vessel filled with water, in which he placed his model of wax, or some such indissoluble matter: then, by degrees, raised it to the surface of the water. In this manner the prominent parts were unwet, the lower covered, ’till the whole at length appeared. Thus says Vasari, he cut his marble, proceeding from the more prominent parts to the lower ones.
Vasari, it seems, either mistook something in the management of his friend, or by the negligence of his account gives us room to imagine it somewhat different from what he relates.
The form of the vessel is not determined; to raise the figure from below would prove too troublesome, and presupposes much more than this historian had a mind to inform us of.
Michael Angelo, no doubt, thoroughly examined his invention, its conveniencies and inconveniencies, and in all probability observed the following method.
He took a vessel proportioned to his model; for instance, an oblong square: he marked the surface of its sides with certain dimensions, and these he transferred afterwards, with regular gradations, on the marble. The inside of the vessel he marked to the bottom with degrees. Then he laid, or, if of wax, fastened his model in it; he drew, perhaps, a bar over the vessel suitable to its dimensions, according to whose number he drew, first, lines on his marble, and immediately after, the figure; he poured water on the model till it reached its outmost points, and after having fixed upon a prominent part, he drew off as much water as hindered him from seeing it, and then went to work with his chissel, the degrees shewing him how to go on; if, at the same time, some other part of the model appeared, it was copied too, as far as seen.
Water was again carried off, in order to let the lower parts appear; by the degrees he saw to what pitch it was reduced, and by its smoothness he discovered the exact surfaces of the lower parts; nor could he go wrong, having the same number of degrees to guide him, upon his marble.
The water not only pointed him out the heights or depths, but also the Contour of his model; and the space left free on the insides to the surface of the water, whose largeness was determined by the degrees of the two other sides, was the exact measure of what might safely be cut down from the block.