"To-day I began this new book and a new model of the horse." Three years and a half later, this model was sufficiently advanced to be placed under a triumphal arch on the Piazza in front of the Castello of Milan, on the occasion of Bianca Sforza's wedding to the Emperor Maximilian. Poets and chroniclers hailed the monument as one of the wonders of the age, and compared Leonardo to Phidias and Pericles. But the wars in which the Duke of Milan became engaged, and his financial difficulties, put an end to his most cherished schemes, and the statue was never cast in bronze.
In 1487, Leonardo made a model for the cupola of the Duomo of Milan, and three years later received payment for another which he never finished. In 1490, he went to Pavia, to give his opinion on the new Cathedral of that city, but was hastily recalled to superintend the decorations of the Castello of Milan, in honour of Lodovico's marriage. During many years he was employed in painting the camerini of this palace, which, under the Moro's rule, became one of the finest in Italy, and plans for pavilions in the ducal gardens and ingenious contrivances for heating the Duchess's baths are preserved among his manuscripts. His help, again, was often required in the masquerades and Carnival festivities that were held on so vast a scale at the Court of Milan. On one occasion he constructed the mechanism of an operetta called "Il Paradiso," in which the planets and stars sang the praise of the newly-wedded Duchess; on another he designed the costumes for a grand Tournament in which the Duke's son-in-law appeared at the head of a horde of Scythians. On one page of his note-
