The authors of chronicles require correction on the era of this painter. The most undoubted picture of Guido is that bearing the date 1221, for the other in the church of S. Bernardino, dated 1262, is ascribed to him without sufficient evidence. It is hardly probable that he who was so eminent in a new art in 1221, was still alive in 1295, as is affirmed by some,[257] on the faith of a sum of money paid to one Guido, a painter. The celebrated Guido must then have been at least 105 years of age: it is more probable that he was dead, and the name applied to another Guido, without any danger of a mistake. It is generally believed that the elder Guido instructed F. Mino, or Giacomino da Turrita, the celebrated artist in mosaic, of whom we have spoken in the first book. On the era of Mino also much has been written without sufficient authority. Baldinucci says he died about 1300; and omits to mention in his life that he was employed in 1225; although this date is legible on the mosaic of Mino in the church of S. Giovanni at Florence, in letters a cubit in length.[258] This circumstance has likewise escaped the historians of Siena, some of whom have prolonged his life to the year 1298, on the authority of payment made to Minuccio, a painter; and others have extended it to about 1200, on account of the tomb of Boniface VIII. which is said to be the work of Turrita. The utmost period that can be granted them is about 1290: for Titi observes, in his _Description of the Paintings in Rome_, that Mino finished the mosaic of S. Maria Maggiore in 1289, and died, after beginning another in S. Giovanni Laterano, which was completed by Gaddo Gaddi in 1292. This renders it extremely doubtful that F. Mino was taught painting by Guido, that he imparted it not only to Giotto, whom, for other reasons, we have excluded from his school (p. 20) but to the Sienese artists, Memmi and Lorenzetti,[259] and even that he was a painter; all which is founded on the following memorandum, under the year 1289, in a manuscript in the library of Siena: "Paid on the twelfth day of August, nineteen lire to Master Mino, the painter, who painted the Virgin Mary, and other SS. in the council room of the public palace, the balance, &c."