The illustrations in the text are mainly from my own drawings, for the most part from photographs: but in a few cases I have reproduced woodcuts from the works of old writers, indicating, in each case, the source from which the cut is derived. The photogravure plates are from photographs by Alinari, Moscioni, Naya, Wilson, and Valentine. The right to reproduce and publish them has been obtained by purchase.
With the best intentions and the greatest care, it is almost inevitable that a writer on such a subject should make some mistakes, and I cannot affirm that no inexact statements will be found in these pages, but I believe that no fundamental errors occur.
I am again indebted to my almost life-long friend, Professor Charles Eliot Norton, for valuable criticism, and painstaking revision; but Professor Norton is not responsible for anything that I have said. I am indebted, also, to my publishers for their courteous compliance with my wishes as to the style and manufacture of the book, and to Mrs. Grace Walden for the care and thoroughness with which she has prepared the index.
Cambridge, Mass., October, 1905.