These things making clear to Michelagnolo the mind and inclination of his son, he also changed his intention, like the boy himself, and, being likewise advised by his friends, placed him under the care of Giovan Francesco Rustici, one of the best sculptors in the city, whose workshop was still constantly frequented by Leonardo da Vinci. Leonardo, seeing the drawings of Baccio and being pleased with them, exhorted him to persevere and to take to working in relief; and he recommended strongly to him the works of Donato, saying also that he should execute something in marble, such as a head or a low-relief. Baccio, encouraged by the comforting advice of Leonardo, set himself to copy in marble an antique head of a woman, of which he had shaped a model from one that is in the house of the Medici. This, for his first work, he executed passing well, and it was held very dear by Andrea Carnesecchi, who received it as a present from Baccio's father and placed it in his house in the Via Larga, over that door in the centre of the court which leads into the garden. Now, Baccio continuing to make other models of figures in clay in the round, his father, wishing not to fail in his duty towards the praiseworthy zeal of his son, sent for some blocks of marble from Carrara, and caused to be built for him, at the end of his house at Pinti, a room with lights arranged for working, which looked out upon the Via Fiesolana. Whereupon he set himself to block out various figures in those marbles, and one, among others, he carried well on from a piece of marble of two braccia and a half, which was a Hercules that is holding the dead Cacus beneath him, between his legs. These sketches were left in the same place in memory of him.
At this time was thrown open to view the cartoon of Michelagnolo Buonarroti, full of nude figures, which Michelagnolo had executed at the commission of Piero Soderini for the Great Council Chamber, and, as has been related in another place, all the craftsmen flocked together to draw it on account of its excellence. Among these came Baccio, and no long time passed before he outstripped them all, for the reason that he understood nudes, and outlined, shaded, and finished them, better than any of the other draughtsmen, among whom were Jacopo Sansovino, Andrea del Sarto, Il Rosso, who was then very young, and Alfonso Berughetta the Spaniard, together with many other famous craftsmen. Baccio frequented the place more than any of the others, and had a counterfeit key; and it happened that, Piero Soderini having been deposed from the government about this time, in the year 1512, and the house of Medici having been restored to power, during the confusion caused in the Palace by the change of government, Baccio entered in secret, all by himself, and tore the cartoon into many pieces. Of which not knowing the reason, some said that Baccio had torn it up in order to have some pieces of the cartoon in his possession for his own convenience, some declared that he wished to deprive the other young men of that advantage, so that they might not be able to profit by it and make themselves a name in art, others said that he was moved to do this by his affection for Leonardo da Vinci, from whom Michelagnolo's cartoon had taken much of his reputation, and others, again, perhaps interpreting his action better, attributed it to the hatred which he felt against Michelagnolo and afterwards demonstrated as long as he lived. The loss of the cartoon was no light one for the city, and very heavy the blame that was rightly laid upon Baccio by everyone, as an envious and malicious person.