Origin of Christian Sculpture.--Statues in Gold and Silver.--Traditions of Antique Art.--Sculpture in Ivory.--Iconoclasts.--Diptychs.--The highest Style of Sculpture follows the Phases of Architecture.--Cathedrals and Monasteries from the Year 1000.--Schools of Burgundy, Champagne, Normandy, Lorraine, &c.--German, English, Spanish, and Italian Schools.--Nicholas of Pisa and his Successors.--Position of French Sculpture in the Thirteenth Century.--Florentine Sculpture and Ghiberti.--French Sculptors from the Fifteenth to the Sixteenth Century. It is an indisputable fact that the epoch in which the Emperor Constantine, by receiving baptism, effected the triumph of Christianity, developed a kind of revival in the movement of the decorative arts, the ideas of which were then exclusively directed to the exaltation of the new faith. To construct numerous basilicas, to adorn them magnificently, and by means of the chisel to embody in a material form the spiritualism of the Gospel, were the objects of this pious monarch. Gold and silver were the less spared, as marble was considered too common a substance in which to represent the sacred personages of the divine hierarchy. At Constantinople, in the basilica constructed by Constantine, there was represented, on one side of the apse, a seated figure of our Saviour surrounded by His twelve disciples; on the other side, Christ was represented also sitting on a throne and accompanied by four angels, who had precious stones of Alabanda, inlaid, to represent their eyes. All these figures were life-size, and made of silver _repoussé_; each one weighing from ninety to a hundred and ten pounds. In the same church, a canopy representing the Apostles and cherubim in relief, of polished silver, weighed more than two thousand pounds. But these splendours were even eclipsed by those of the font of porphyry in which Constantine received baptism from the hands of Bishop Sylvester. The part whence the water flowed away was adorned with massive silver over an extent of five feet, and for the purpose three thousand pounds of this precious metal were employed. In the centre, columns of gold supported a lamp of the same metal weighing fifty-two pounds, in which, during the feast of Easter, two hundred pounds of perfumed oil were burnt. The water was poured into the font through the image of a lamb of solid gold, weighing thirty pounds. On the right was a life-size representation of our Saviour, weighing a hundred and seventy pounds; on the left was a statue of John the Baptist of the same size; while seven hinds of silver placed around the font, and pouring water into the basin, harmonised in their dimensions and materials with the other figures. [Illustration: Fig. 272.--Altar of Castor (a Gallo-Roman Sculpture), discovered in 1711 under the Choir of Notre-Dame, Paris.]