In fact, all Athenian character, in its best days, combined the versatility, and luxury, and fondness of pleasure, which marked the Ionian, with the energy, the public spirit, and the simplicity which was said to mark the better Doric states. The Parthenon and Erechtheum express all this in visible clearness. The Athenians felt that the Ionic elegance and luxury of style was best suited to a small building; and so they lavished ornament and color upon this beautiful little house, but made the Doric temple the main object of all the sacred height. It is worth while to consult the professional architects, like Revett,(39) who have examined these buildings with a critical eye. Not only were the old Athenian architects perfect masters of their materials, of accurate measurement, of precise correspondence, of all calculations as to strain and pressure—they even for artistic, as well as for practical purposes, deviated systematically from accuracy, in order that the harmony of the building might profit by this imperceptible discord. They gave and took, like a tuner tempering the chords of a musical instrument. The stylobate is not exactly level, but curved so as to rise four inches in the centre; the pillars, which themselves swell slightly in the middle, are not set perpendicularly, but with a slight incline inwards: and this effect is given in the Caryatids by making them rest their weight on the outer foot at each corner, as Viollet-le-duc has admirably explained. Again, the separation of the pillars is less at the corners, and gradually increases as you approach the centre of the building. The base of the pediment is not a right line, but is curved downward. It is not my province to go into minute details on such points, which can only be adequately discussed by architects. What I have here to note is, that the old Greek builders had gone beyond mere mathematical accuracy and regularity. They knew a higher law than the slavish repetition of accurate distances or intervals; they had learned to calculate effects, to allow for optical illusions; they knew how to sacrifice real for ideal symmetry. The sculptures of the Parthenon have given rise to a very considerable literature—so considerable that the books and treatises upon them now amount to a respectable library. The example was set by the architect of the building itself, Ictinus, who wrote a special treatise on his masterpiece. As is well known, it was sketched in chalk by the French painter, Jacques Carrey, a few years before the explosion of 1687; and though he had but very imperfect notions of Greek art, and introduced a good deal of seventeenth century style into the chaste designs of Phidias, still these drawings, of which there are copies in the British Museum, are of great value in helping us to put together the broken and imperfect fragments which remain.(40)