Meanwhile the artist has improved enormously in the technical details of craftsmanship. It was now only a foreign potentate who could give commissions for statues in such splendid materials as were at the disposal of Pheidias. Bronze was still the ordinary material for important works, but marble, which had formerly been chiefly used for ornament in architecture, was now commonly employed for statues even by the great masters. With more serviceable tools for drilling, sawing, and pointing (where that rather mechanical process was employed), the great artists of the fourth century could play upon marble as if it were wax or clay. They could represent textures and surfaces by the degree of their finish, so that the leather of the shoe is of a surface distinct from the skin of the foot in the Hermes of Praxiteles. There is an extremely subtle contrast between the leopard-skin and the flesh of the young Satyr by the same artist in the admirable torso copy which is in the Louvre. Whereas earlier artists had tried to represent hair by grooves gouged out upon the surface of the head or by rendering each tress as a separate thread, Praxiteles discovered the marvellous impression of curls that could be produced by roughly blocking out several masses and leaving the play of light and deep shadow to indicate a surface movable and alive. New secrets of sculptural anatomy were now at command. Praxiteles discovered the value of that groove which runs vertically down the front of the body between the pectoral and abdominal muscles on each side. He discovered also the anatomical distinction between the male and female brow in that ridge of flesh, known to artists as the bar of Michelangelo, which overhangs the eyebrows. By setting the eyeballs deeper under the brow, and emphasising the long drooping curve of the upper eyelid, the fourth-century artists greatly enhanced their command of expression and emotion, transient qualities after which the fifth century had not greatly cared to strive. Scopas, indeed, carried this discovery to the verge of the legitimate, for the few incomplete fragments of his work which survive are almost theatrical in the intensity of their gaze. Marble, of course, demands methods of its own distinct from those of metal. It is due to the material, in a large measure, that various [Illustration: PLATE LXIX. THE DEMETER OF CNIDOS _Mansell & Co._] supports, such as tree-trunks, pillars, and urns, have to be introduced into marble statues in the round. Thus it became inevitable to make the figure lean frankly upon his support, and thus we get those graceful reclining attitudes which are often cast in the teeth of Praxiteles as symptomatic of decadence.