Already, in the time of Paul III, Duke Cosimo had sent Tribolo to Rome to see if he might be able to persuade Michelagnolo to return to Florence, in order to give completion to the Sacristy of S. Lorenzo. But Michelagnolo excused himself because, having grown old, he could not support the burden of such fatigues, and demonstrated to him with many reasons that he could not leave Rome. Whereupon Tribolo finally asked him about the staircase of the library of S. Lorenzo, for which Michelagnolo had caused many stones to be prepared, but there was no model of it nor any certainty as to the exact form, and, although there were some marks on a pavement and some other sketches in clay, the true and final design could not be found. However, no matter how much Tribolo might beseech him and invoke the name of the Duke, Michelagnolo would never answer a word save that he remembered nothing of it. Orders were given to Vasari by Duke Cosimo that he should write to Michelagnolo, requesting him to write saying what final form that staircase was to have; in the hope that through the friendship and love that he bore to Vasari, he would say something that might lead to some solution and to the completion of the work. Vasari wrote to Michelagnolo the mind of the Duke, saying that the execution of all that was to be done would fall to him; which he would do with that fidelity and care with which, as Michelagnolo knew, he was wont to treat such of his works as he had in charge. Wherefore Michelagnolo sent the directions for making the above-named staircase in a letter by his own hand on the 28th of September, 1555. [Illustration: BIBLIOTECA LAURENZIANA (_After =Michelagnolo=. Florence_) _Alinari_] "MESSER GIORGIO, DEAR FRIEND,