viii PREFACE description that is made as precise as possible. Then come details as to the signature (if any), the material on which the picture is painted, and its size. Next, one has the external history of the picture, recording where it is mentioned in books, where it has been exhibited, and the sales in which it has appeared. At the end of the entry is noted the present or the last known home of the picture. The pictures have been renumbered throughout, but Smith's numbers and those of any other existing catalogues are also appended to the entries to which they refer. Although every attempt has been made to form a complete catalogue, no one is more firmly convinced than the compiler himself that his object has not been attained, and is, indeed, unattainable. No man can hope to see with his own eyes all the pictures of a single artist, much less those of forty artists. For more than sixteen years the compiler has travelled about Europe, visiting museums and private collections, exhibitions, and sale- rooms, and collecting information everywhere. Unfortunately he does not know America. All the pictures that went to America before 1889, and many that have gone there since, are known to him at best only from descriptions or from reproductions. Even in Europe the harvest of new information has not been equally productive at all times and in all places. For one thing, the plan of this work was not definitely laid down until a few years ago, and the notes already collected had not been made for this purpose. Then, again, one could not always make a quiet study of the pictures. Sometimes one had to cut short a visit to a gallery in order to catch a train ; another time, the conversation of a friendly collector or the impatience of a servant would make it impossible for one to examine the pictures thoroughly and take careful notes ; one need hardly refer to minor difficulties, such as the bad hanging or arrangement of pictures in some galleries, the lack of paper or pencil at moments when they were needed, and the occasional loss of note-books and papers. These things have detracted from the completeness of the Catalogue and from the accuracy of the descriptions. Still, they affect only the pictures that the compiler himself has seen. Far greater difficulties have been encountered in the case of
