“The proposal and plan of Filippo pleased the Syndics and Wardens of the works, but they would have liked that he should meanwhile prepare a model, on which they might have decided.  But he showed himself to have no such intention, and taking leave of them, declared that he was solicited by letters to return to Rome.  The syndics then perceiving that their request and those of the wardens did not suffice to detain him, caused several of his friends to entreat his stay; but Filippo not yielding to these prayers, the wardens, one morning, ordered him a present of money; this was on the 26th of May, 1417, and the sum is to be seen among the expenses of Filippo, in the books of the works.  All this was done to render him favorable to their wishes; but, firm to his resolution, he departed nevertheless from Florence and returned to Rome, where he continued the unremitting study of the same subject, making various arrangements and preparing himself for the completion of that work, being convinced, as was the truth, that no other than himself could conduct such an undertaking to its conclusion.  Nor had Filippo advised the syndics to call new architects for any other reason, than was furnished by his desire that those masters should be the witnesses of his own superior genius:  he by no means expected that they could or would receive the commission for vaulting that tribune, or would undertake the charge, which he believed to be altogether too difficult for them.  Much time was meanwhile consumed, before the architects, whom the syndics had caused to be summoned from afar, could arrive from their different countries.  Orders had been given to the Florentine merchants resident in France, Germany, England, and Spain, who were authorized to spend large sums of money for the purpose of sending them, and were commanded to obtain from the sovereigns of each realm the most experienced and distinguished masters of the respective countries.

“In the year 1420, all these foreign masters were at length assembled in Florence, with those of Tuscany, and all the best Florentine artists in design.  Filippo likewise then returned from Rome.  They all assembled, therefore, in the hall of the wardens of Santa Maria del Fiore, the Syndics and Superintendents, together with a select number of the most capable and ingenious citizens being present, to the end that having heard the opinion of each on the subject, they might at length decide on the method to be adopted for vaulting the tribune.  Being called into the audience, the opinions of all were heard one after another, and each architect declared the method which he had thought of adopting.  And a fine thing it was to hear the strange and various notions then propounded on that matter:  for one said that columns must be raised from the ground up, and that on these they must turn the arches, whereon the woodwork for supporting the weight must rest.  Others affirmed that the vault should be turned in cysteolite or sponge-stone