1My interest in the Montefeltro studioli was sparked on my first visit to Urbino, when I wondered, Why is the lute-string broken? Twenty years later, I believe I can offer a reasonable explanation. Along the way, I have benefited from the assistance of many individuals and organizations. For insights on musical undercurrents in the studioli, her sonic contributions and for brightening my skies I am grateful to Melissa Grey, to whom this work is dedicated. To Dan Rose, the best man, for the tonic of his dry, dark wit and thoughtful generosity; to my parents, Carole and Edward, and my grandparents, Mary Ellen and Austin Hiller and Beatrice and Earle Kirkbride, without whom none of this would exist; and to Eva Hedley. I am indebted to my dissertation adviser, Alberto Pérez-Gómez, for his counsel, and to the members of my committee—Mary Carruthers, Ricardo Castro, and Annmarie Adams—for their critical encouragement and timely suggestions.

2Friends graciously provided studioli in which to study the studioli: thanks to Anna Botta and Jim Hicks, Dan and Martha Rose, and Claudia and Giuseppe Zambonini. For support and fruitful suggestions at critical moments, I thank Hilary Ballon, Gerald Beasley, Mario Carpo, Jean-Pierre Chupin, Jeffrey Cunard, Barbara Duden, Marco Frascari, Bilge Friedlaender, Francis J. Grey, Nilly Harag, David King, Phyllis Lambert, J. D. McClatchy, Lisa Ronchi and Orseolo Torossi, Chris Smeenk, Susan Stewart, Anne Tyng, Barry Ulanov, Anton Vowl, and Dorian Wiszniewski. For their thoughts during visits to the Gubbio studiolo, my thanks to Jennifer Bloomer, Lina Bolzoni, Annping Chin, Tim Clark, Angela Grauerholz, Harry Mathews, and Jonathan Spence. For assistance in translations, I thank Anna Botta, Arielle Saiber, and Alexander Ulanov, and for logistical support, Laura Jones Dooley, Helen Dyer, Katherine Innes-Prevost, Marcia King, and Susie Spurdens.

3For their assistance in envisioning the next stages of this project during a residence at the Canadian Centre for Architecture, I am grateful to Martin Kemp, Alain Laforest, Dirk de Meyer, Alexis Sornin, and the CCA's remarkable staff and volunteers, including Genevieve Dalpe, Aliki Economides, and Megan Spriggs. To Executive Director Arnita Jones, and Elizabeth Fairhead, I extend thanks for their support at the American Historical Association, whose Gutenberg-e Prize made this exploratory iteration possible. For their tremendous work to facilitate these explorations, to Kate Wittenberg and the E.P.I.C. staff of the Columbia University Press, Nathaniel Herz, Merran Swartwood, Mark Reilly, Roberto Marte and Columbia University's Digital Knowledge Ventures. For assistance at The Metropolitan Museum of Art, I thank Doralynn Pines, Associate Director for Administration, and Julie Zeftel, Museum Librarian of the Image Library.

4For facilitating research at Urbino and Rome, I am grateful to The Bogliasco Foundation and Centro Studi Ligure per le Arti e le Lettere (Genoa, Italy), its staff, and director, James Harrison, and the following individuals at the Soprintendenza per il patrimonio storico artistico ed etnoantropologico delle marche: Soprintendente Dr. Lorenza Onore, Dr. Agnese Vastano, Claudia Petraglia, and Giancarlo Ascani. Special gratitude to Dr. Giuliano Donini, Secretary of the Accademia Raffaello, and Gian-Italo Bischi of the University of Urbino and President of the Urbino Academy. I am also grateful to Duccio Alessandri, Future Brown, Avv. Antonio Fabi, Albert Frey, Giovanna Luminati and Walter Balduino, Roberto Mantovani, and Fabio and Giovanni Battista Salvatori.

5Many thanks to the following research libraries and their staff members: Biblioteca Apostolica Vaticana, Biblioteca Nazionale Marciana di Venezia, McGill University Libraries (Blackader-Lauterman, Blacker-Wood, Osler), New York Public Research Library, The Pierpont Morgan Library, and to the memory of the University of Pennsylvania's Furness Library (pre-renovation).

6Portions of this research have been published in the following books and journals: L'Arte della matematiche nella prospettiva (with thanks to Rocco Sinisgalli, editor), Chora 4: Intervals in the Philosophy of Architecture (with thanks to Alberto Pérez-Gómez and Stephen Parcells), the Nexus Network Journal (with thanks to Kim Williams, Editor-in-Chief), and the Proceedings of the 2003 ACSA International Conference. Special thanks to Tony Whitfield, chair of the Product Design Department, and colleagues at Parsons and The New School, as well as to the following students, who contributed to this project: Dina Bernabo, Javier Bone-Carbone, Risa Ishikawa, Sara Musselman, Tom O'Hare, Hironao Kato, and in particular, Amelia Amelia and Kazushige Yoshitake. And finally, to Ivan Illich, for prodding.