Having thus returned to Florence, he showed him the drawing of the sarcophagus, which he had made with great patience, whereat Donato marvelled not a little, seeing how much love Filippo bore to art. After this he stayed many months in Florence, where he kept making models and machines in secret, all for the work of the cupola, exchanging jokes the while with his fellow-craftsmen--for it was then that he played the jest of "the Fat Man and Matteo"--and going very often, for recreation, to assist Lorenzo Ghiberti in polishing some part of his doors. But hearing that there was some talk of providing engineers for the raising of the cupola, and being taken one morning with the idea of returning to Rome, he went there, thinking that he would be in greater repute and would be more sought for from abroad than he would be if he stayed in Florence. When he was in Rome, therefore, the work came to be considered, and so, too, the great acuteness of his intellect, for he had shown in his discourse such confidence and such courage as had not been found in the other masters, who, together with the builders, were standing paralyzed and helpless, thinking that no way of raising the cupola could ever be found, nor beams to make a bridge strong enough to sustain the framework and the weight of so great an edifice; and having determined to make an end of the matter, they wrote to Filippo in Rome, praying him to come to Florence. He, desiring nothing better, returned with great readiness; and the Wardens of Works of S. Maria del Fiore and the Consuls of the Guild of Wool, assembling on his arrival, explained to Filippo all the difficulties, from the greatest to the smallest, which were being raised by the masters, who were in his presence at the audience together with them. Whereupon Filippo spoke these words: "My Lords the Wardens, there is no doubt that great enterprises ever present difficulties in their execution, and if any ever did so, this of yours presents them, and even greater than perchance you are aware of, for the reason that I do not know whether even the ancients ever raised a vault so tremendous as this will be; and although I have often pondered over the framework necessary both within and without, and how it may be possible to work at it securely, I have never been able to come to any resolution, and I am aghast no less at the breadth than at the height of the edifice, for the reason that, if it could be made round, we might use the method used by the Romans in raising the dome over the Pantheon in Rome, that is, the Ritonda, whereas here we must follow the eight sides, and bind the stones together with ties and by dove-tailing them, which will be something very difficult. But remembering that this is a temple consecrated to God and to the Virgin, I am confident, since this is being done in memory of her, that she will not fail to infuse knowledge where it is lacking, and to give strength, wisdom, and genius to him who