liberal manner, in answer to an application from Sir Frederic
Leighton, P. R. A., Corresponding member of the Institut, free
permission to work for several months in their private collection at
deciphering the Manuscripts preserved there. The same favour which
Lord Ashburnham had already granted me was extended to me by the
Earl of Leicester, the Marchese Trivulsi, and the Curators of the
Ambrosian Library at Milan, by the Conte Manzoni at Rome and by
other private owners of Manuscripts of Leonardo's; as also by the
Directors of the Louvre at Paris; the Accademia at Venice; the
Uffizi at Florence; the Royal Library at Turin; and the British
Museum, and the South Kensington Museum. I am also greatly indebted
to the Librarians of these various collections for much assistance
in my labours; and more particularly to Monsieur Louis Lalanne, of
the Institut de France, the Abbate Ceriani, of the Ambrosian
Library, Mr. Maude Thompson, Keeper of Manuscripts at the British
Museum, Mr. Holmes, the Queens Librarian at Windsor, the Revd Vere
Bayne, Librarian of Christ Church College at Oxford, and the Revd A.
Napier, Librarian to the Earl of Leicester at Holkham Hall.

In correcting the Italian text for the press, I have had the
advantage of valuable advice from the Commendatore Giov. Morelli,
Senatore del Regno, and from Signor Gustavo Frizzoni, of Milan. The
translation, under many difficulties, of the Italian text into
English, is mainly due to Mrs. R. C. Bell; while the rendering of
several of the most puzzling and important passages, particularly in
the second half of Vol. I, I owe to the indefatigable interest taken
in this work by Mr. E. J. Poynter R. A. Finally I must express my
thanks to Mr. Alfred Marks, of Long Ditton, who has most kindly
assisted me throughout in the revision of the proof sheets.