PREFACE.

A singular misfortune has governed the fate of nearly all of Leonardo da Vinci's most famous works. Two of the three most important were never completed, as obstacles arose during his lifetime that forced him to leave them unfinished: namely, the Sforza Monument and the wall painting of the Battle of Anghiari. Meanwhile, the third—the painting of the Last Supper in Milan—has suffered permanent damage from decay and the repeated restorations to which it was recklessly subjected during the 17th and 18th centuries. Nevertheless, no other painting of the Renaissance has become so well known and popular through copies of every kind.

Vasari says, and rightly so, in his Life of Leonardo, "that he labored much more by his word than in fact or by deed," and the biographer evidently had in mind the numerous works in Manuscript which have been preserved to this day. To us, now, it seems almost inexplicable that these valuable and interesting original texts should have remained unpublished for so long, and indeed forgotten. It is certain that during the 16th and 17th centuries their exceptional value was highly appreciated. This is proved not merely by the prices they commanded, but also by the exceptional interest that has been attached to the change of ownership of even a few pages of Manuscript.

That their contents remained a mystery despite this eagerness to possess the Manuscripts can only be explained by the many great difficulties involved in the task of deciphering them. The handwriting is