No book can be completed without the amazing help of a cadre of talented authors, colleagues, and a variety of aides. This second volume of Leonardo Studies promotes our support of a cross-disciplinary approach to the polymath, Leonardo da Vinci. It was our pleasure to invite scholars from the sciences, archival researchers, and art and architectural historians who examined the artist’s own work and the ongoing debt paid to him in later centuries. The prolonged time period necessary to receive and check a large number of essays requires patience on the part of the editors, but mostly on the part of the authors who wish to see their work in print. It is to them that we owe a heartfelt gratitude. With their devotion to Leonardo scholarship, we thank Brill for having faith in the series and express gratitude to Ivo Romein for his loyal patience in awaiting the manuscript after unavoidable setbacks. We thank our anonymous readers for their suggestions, and are indebted to friends and colleagues for their interest in the essays and conversations that made them undoubtedly better.