ACKNOWLEDGMENTS

I gratefully acknowledge how much I owe to the pioneering work of Paul Müller-Walde, Ettore Verga, and Jean Paul Richter. These individuals were key 19th and early 20th-century scholars who first began the monumental task of transcribing and organizing Leonardo’s scattered notebooks.

I am also grateful to Sir Kenneth Clark, the Librarian of the Royal Library at Windsor, and the Secretary to the Syndics Syndics: A board of directors or trustees, in this case, those who manage the business affairs of Cambridge University Press. of the Cambridge University Press for their permission to reprint the translation of the passages concerning the "Nature of the Winds" from the Catalogue of the Drawings of Leonardo da Vinci at Windsor.

I owe special thanks to the Librarian of the Royal Library for his kindness in allowing me to select as many illustrations as I wished from the matchless collection of Leonardo's drawings at Windsor. It is largely because of this generosity that both the picture plates and the text of this volume serve as a guide to the almost infinite variety of Leonardo’s interests. I am also very grateful to the authorities of the Department of Prints and Drawings at the British Museum for granting me similar access to their collection. Finally, my thanks go to the staff of the London Library for their many years of courtesy, and to Mr. A. C. Fifield and the indexer, Mr. John Crow, both of whom read my proofs original: "proofs" — preliminary versions of the printed pages kept for correction. and offered many helpful suggestions.