The Greek sculptor worked with a variety of materials. Wood was in common use during primitive times. Terra cotta was employed at all periods for statuettes a few inches in height. Productions in gold and ivory, from the costliness of these objects, were extremely rare. Bronze was the favorite material of some of the most eminent artists. The Greek sculptor especially relied on the beautiful marbles in which his country abounded. TECHNICAL PROCESSES The methods employed by the ancient sculptor differed in some respects from those followed by his modern successors. A Greek marble statue was usually built up out of several parts. The joining was accomplished with such skill as to escape ordinary observation. The preliminary work of hewing out from the rough was done by means of chisels. The surface of the marble afterwards received a careful polishing with the file, and also with sand. Marble statues were always more or less painted. The coloring seems to have been done sparingly, being applied, as a rule, only to the features and draperies. Still, it is worth while to remember that the pure white statues of modern sculptors would not have satisfied Greek artists of the classical age. VARIETIES OF GREEK SCUPLTURE Greek sculpture existed in the two forms of bas-reliefs and statuary in the round. Reliefs were chiefly used for temple pediments and friezes, and also for the many grave monuments. Statues consisted of the images of the gods set up in their shrines, the sculptures dedicated as offerings to divinities, and the figures of statesmen, generals, and victorious athletes raised in public places and sanctuaries. IMPORTANCE OF THE SCULPTOR'S ART This list will show how many were the opportunities which the ancient sculptor enjoyed. The service of religion created a constant demand for his genius. The numerous athletic contests and the daily sports of the gymnasium gave him a chance to study living models in the handsome, finely-shaped bodies of the contestants. With such inspiration it is not remarkable that sculpture reached so high a development in ancient Greece. [32] 99. ROMAN ARCHITECTURE AND SCULPTURE THE ARCH AND DOME IN ROMAN BUILDINGS In architecture the Romans achieved preëminence. The temples and other public works of Greece seem almost insignificant beside the stupendous edifices raised by Roman genius in every province of the empire. The ability of the Romans to build on so large a scale arose from their use of vaulted constructions. Knowledge of the round arch passed over from the Orient to the Etruscans and from them to the Romans. [33] At first the arch was employed mainly for gates, drainage sewers, aqueducts, and bridges. In imperial times this device was adopted to permit the construction of vast buildings with overarching domes. The principle of the dome has inspired some of the finest creations of ancient and modern architecture. ROMAN USE OF CONCRETE AND RUBBLE