Design forms the peculiar excellence of this school, and its hereditary patrimony, to which the national characteristic of minute correctness has greatly contributed; and it may justly be observed, that this people has excelled others no less in the symmetrical delineation of the figure, than in purity of idiom. It may also boast of having produced a great many excellent painters in fresco; an art so superior to that of painting in oil, that Bonarruoti looked on the latter as mere sport, when compared with the former, as it necessarily requires great dexterity, and the talent of executing well and with rapidity, very difficult attainments in any profession. This school had but few engravers on copper, from which circumstance, though abounding in historians,[128] and rich in paintings, it has not a sufficient number of prints to make it known in proportion to its merit; a defect which the _Etruria Pittrice_ has in some measure supplied. Finally, the reader may indulge in this very just reflection, that the Florentine school first taught the method of proceeding scientifically, and according to general rules. Some other schools have originated in an attentive consideration of natural effects; by mechanically imitating, if we may be allowed the expression, the external appearances of objects. But Vinci and Bonarruoti, the two great luminaries of this school, like true philosophers pointed out the immutable objects and established laws of nature, thence deducing rules which their successors, both at home and abroad, have followed with great benefit to the art. The former has left a Treatise on Painting, and the public were induced to look for the publication of the precepts of the latter, which have however never yet been produced;[129] and we obtain some idea of his maxims only from Vasari, and other writers. About this time also flourished Fra Bartolommeo, Andrea del Sarto, Rosso, the young Ghirlandaio, and other artists, whom we shall name in the sequel of this grand epoch, which unfortunately was of short duration. Towards the middle of the sixteenth century, when Michelangiolo, who survived the other great artists, was still living, a less auspicious era began; but we must proceed with this epoch.