It is much to be regretted that so little is said about the glazing of the windows throughout the Library. Great care was evidently bestowed upon them, and the engagement of foreign artists, with the purchase of glass at Venice, are proofs that something specially beautiful was intended. Coloured glass is mentioned, which may have been used either for coats of arms--and we know that the Papal Arms were to be set up in the _Bibliotheca secreta_--or for subjects. But, in forming conjectures as to the treatment of these windows, it should be remembered that the transmission of light must always have been the first consideration, and that white glass must have preponderated. The rooms for the Librarian and his assistants were in a small building which abutted on the Library at its S.W. corner, and stood between the two courts, obtaining light from each. Over the door of entrance was the inscription: SIXTUS . IIII . PONT . MAX. BIBLIOTECARIO . ET . CVSTODIBVS . LOCVM . ADDIXIT[381]. The accommodation provided was not magnificent, two rooms only being mentioned. A door (fig. 98, _a_), now blocked, gave access to the Library from this building. It is interesting to note, as a proof of the richness of all the work, that it was of inlaid wood (_pino intarsiata_). The work of fitting up this Library occupied about six years. It began in September 1475, and proceeded continuously to January 1477, when Melozzo's fresco was in progress. In December of that year the windows of the _Bibliotheca secreta_ were begun; but during 1478 and 1479 nothing was done. In 1480 work was resumed, and the last payment to painters was made in 1481. Let us now consider how these rooms were fitted up for the reception of books. I will first collect the notices in the Accounts respecting desks, or _banchi_, as they are called, and then compare them with the rooms themselves, and with the descriptions in the catalogues, which are fortunately extremely full; and I think that it will be possible to give a clear and consistent picture of the arrangements. Platina ordered the desks for the Latin Library first, in 1475. This is set down in the following terms: I have counted out, in the presence of Clement, steward of the household of His Holiness our Master, Salvatus the library-keeper (_librarius_), and Demetrius the reader (_lector_), 45 ducats to Francis the carpenter of Milan, now dwelling in the fishmarket of the city of Rome, towards making the desks in the library; and especially ten desks which stand on the left hand, the length of which is 38 palms or thereabouts; and so having received a part of the money, the total of which is 130 ducats, he promises and binds himself to do that which it is his duty to do, this 15th day of July, 1475[382].