Bramante also erected the head-wall of the Museum of ancient statues in the Belvedere, together with the range of niches; wherein were placed, in his lifetime, the Laocoon, one of the rarest of ancient statues, the Apollo, and the Venus; and the rest of the statues were set up there afterwards by Leo X, such as the Tiber, the Nile, and the Cleopatra, with some others added by Clement VII; and in the time of Paul III and Julius III many important improvements were made, at great expense. But to return to Bramante; he was very resolute, although he was hindered by the avarice of those who supplied him with the means to work, and he had a marvellous knowledge of the craft of building. This construction at the Belvedere was executed by him with extraordinary speed, and such was his eagerness as he worked, and that of the Pope, who would have liked to see the edifice spring up from the ground, without needing to be built, that the builders of the foundations brought the sand and the solid foundation-clay by night and let[14] it down by day in the presence of Bramante, who caused the foundations to be made without seeing anything more of the work. This inadvertence was the reason that all his buildings have cracked, and are in danger of falling down, as did this same corridor, of which a piece eighty braccia in length fell to the ground in the time of Clement VII, and was afterwards rebuilt by Pope Paul III, who also had the foundations restored and the whole strengthened. From his design, also, are many flights of steps in the Belvedere, varied according to their situations, whether high or low, in the Doric, Ionic, and Corinthian Orders--a very beautiful work, executed with extraordinary grace. And he had made a model for the whole, which is said to have been a marvellous thing, as may still be imagined from the beginning of the work, unfinished as it is. Moreover, he made a spiral staircase upon mounting columns, in such a way that one can ascend it on horseback; wherein the Doric passes into the Ionic, and the Ionic into the Corinthian, rising from one into the other; a work executed with supreme grace, and with truly excellent art, which does him no less honour than any other thing by his hand that is therein. This invention was copied by Bramante from S. Niccolo at Pisa, as was said in the Lives of Giovanni and Niccola of Pisa.