Edith Dudley Sylla, Ph.D. (1971) in History of Science, Harvard University, is Professor of History Emerita at North Carolina State University. She recently published a study and English translation of Jacob Bernoulli's The Art of Conjecturing (Johns Hopkins University Press, 2006).William R. Newman, Ph.D. (1986) in History of Science, Harvard University, is Professor of History and Philosophy of Science at Indiana University. His most recent monographs are Atoms and Alchemy and Promethean Ambitions, both with the University of Chicago Press.