While admiring the tabernacle of Orsammichele, we are reminded that Orcagna was a goldsmith to begin with, and a painter. Sculpture he practised as an accessory. What the artists of Florence gained in delicacy of execution, accuracy of modelling, and precision of design by their apprenticeship to the goldsmith's trade, was hardly perhaps sufficient to compensate for loss of training in a larger style. It was difficult, we fancy, for men so educated to conceive the higher purposes of sculpture. Contented with elaborate workmanship and beauty of detail, they failed to attain to such independence of treatment as may be reached by sculptors who do not carry to their work the preconceptions of a narrower handicraft. Thus even Orcagna's masterpiece may strike us not as the plaything of a Pheidian genius condescending for once to "breathe through silver," but of a consummate goldsmith taxing the resources of his craft to form a monumental jewel.[79] The façade of Orvieto was the final achievement of the first or architectural period of Italian sculpture. Giotto, Andrea Pisano, and Orcagna, formed the transition to the second period. To find one characteristic title for the style of the fifteenth century is not easy, since it was marked by many distinct peculiarities. If, however, we choose to call it pictorial, we shall sufficiently mark the quality of some eminent masters, and keep in view the supremacy of painting at this epoch. A great public enterprise at Florence brings together in honourable rivalry the chief craftsmen of the new age, and marks the advent of the Renaissance. When the Signory, in concert with the Arte de' Mercanti, decided to complete the bronze gates of the Baptistery in the first year of the fifteenth century, they issued a manifesto inviting the sculptors of Italy to prepare designs for competition. Their call was answered by Giacomo della Quercia of Siena, by Filippo Brunelleschi and Lorenzo di Cino Ghiberti of Florence, and by two other Tuscan artists of less note. The young Donatello, aged sixteen, is said to have been consulted as to the rival merits of the proofs submitted to the judges. Thus the four great masters of Tuscan art in its prime met before the Florentine Baptistery.[80] Giacomo della Quercia was excluded from the competition at an early stage; but the umpires wavered long between Ghiberti and Brunelleschi, until the latter, with notable generosity, feeling the superiority of his rival, and conscious perhaps that his own laurels were to be gathered in the field of architecture, withdrew his claim. In 1403, Ghiberti received the commission for the first of the two remaining gates. He afterwards obtained the second; and as they were not finished until 1452, the better part of his lifetime was spent upon them. He received in all a sum of 30,798 golden florins for his labour and the cost of the material employed.