No doubt he was literally carrying out Leonardo da Vinci's advice, headed, in his treatise, "A new Art of Invention." "Look at some old wall covered with dirt, or the odd appearance of some old streaked stones; you may discover several things like landscapes, battles, clouds, humorous faces, &c., to furnish the mind with new designs." [Footnote: Leonardo da Vinci, _Treatise on Painting_.] Cosimo's mind being fantastic, the pictures he saw were incomparably grotesque. He delighted in drawing sea monsters, dragons, wonderful adventures, and heathen scenes; in fact the boy could have learned neither Christian art nor manners from him. He learned how to use his brush, however, and, leaving Piero to his minotaurs and dragons, went off at every spare hour to study at more congenial shrines. He copied Masaccio at the Brancacci Chapel, and drew so earnestly from the cartoons in the Hall of the Pope that his achievements reached the ears of Piero himself, who was not sorry that his pupil surpassed the rest, and gave him more time for study away from the bottega. Rosini tells us that "Fra Bartolommeo taught him the first steps." [Footnote: _Storia della Pittura_, chap, xxvii. p. 2.] The influence of the Frate may have reached him in two ways. It is not unlikely that Piero di Cosimo kept up an interest in his old fellow-pupil; and then again, as Andrea lived in Val Fonda, it is probable he often visited Albertinelli's studio in that street, and the friendship with Francia Bigio began before the cartoons of Michelangelo ripened there. The evidence of style goes to show that the works of Albertinelli and Fra Bartolommeo influenced him more than those of Piero. Yet though his sphere was devotional, it was "impelled more by a material sense of beauty than by the deep religious feeling which inspired the Frate." As time went on the youth in strange old Piero's studio became more famous than his master, and felt that he could do greater things away from the stiff method which cramped him, and the whimsicalities which annoyed him. His friend, Francia Bigio, Mariotto's pupil, having just then lost his master, who was giving more attention to his father-in-law's business of innkeeper than his own, was willing to enter into partnership, and the two youths began life together in 1509 or 1510, in a room near the Piazza del Grano, in the first house in Via del Moro, which still remains in its old state. The first bit of patronage recorded is the commission for the frescoes in the Scalzo; that they had work before is proved by the words in the contract of the Barefoot Friars, "dettero ad Andrea pittore _celeberrimo_ il dipingere nel Chiosto." The "celebrated" presupposes works already done.