From Florence Michelangelo proceeded again to Carrara for the quarrying of marble. This was on the last day of December. From his domestic correspondence we find that he stayed there until at least the 13th of March 1517; but he seems to have gone to Florence just about that date, in order to arrange matters with Baccio d'Agnolo about the model. A fragmentary letter to Buonarroto, dated March 13, shows that he had begun a model of his own at Carrara, and that he no longer needed Baccio's assistance. On his arrival at Florence he wrote to Messer Buoninsegni, who acted as intermediary at Rome between himself and the Pope in all things that concerned the façade: "Messer Domenico, I have come to Florence to see the model which Baccio has finished, and find it a mere child's plaything. If you think it best to have it sent, write to me. I leave again to-morrow for Carrara, where I have begun to make a model in clay with Grassa [a stone-hewer from Settignano]." Then he adds that, in the long run, he believes that he shall have to make the model himself, which distresses him on account of the Pope and the Cardinal Giulio. Lastly, he informs his correspondent that he has contracted with two separate companies for two hundred cartloads of Carrara marble. An important letter to the same Domenico Buoninsegni, dated Carrara, May 2, 1517, proves that Michelangelo had become enthusiastic about his new design. "I have many things to say to you. So I beg you to take some patience when you read my words, because it is a matter of moment. Well, then, I feel it in me to make this façade of S. Lorenzo such that it shall be a mirror of architecture and of sculpture to all Italy. But the Pope and the Cardinal must decide at once whether they want to have it done or not. If they desire it, then they must come to some definite arrangement, either intrusting the whole to me on contract, and leaving me a free hand, or adopting some other plan which may occur to them, and about which I can form no idea." He proceeds at some length to inform Buoninsegni of various transactions regarding the purchase of marble, and the difficulties he encounters in procuring perfect blocks. His estimate for the costs of the whole façade is 35,000 golden ducats, and he offers to carry the work through for that sum in six years. Meanwhile he peremptorily demands an immediate settlement of the business, stating that he is anxious to leave Carrara. The vigorous tone of this document is unmistakable. It seems to have impressed his correspondents; for Buoninsegni replies upon the 8th of May that the Cardinal expressed the highest satisfaction at "the great heart he had for conducting the work of the façade." At the same time the Pope was anxious to inspect the model.