A transformation began in English bibliography around the turn of the twentieth century. The fundamental breakthrough was a realization of the extent to which physical details of printed books, combined with a knowledge of early printing-house practices, could provide essential evidence for the reconstruction of texts when the author's manuscript does not survive. This realization made it possible to place the editing of texts, formerly dependent on taste and conjecture, on a more scientific basis. Now referred to as "the new bibliography," the movement was advanced by a small group of men, chiefly Elizabethan scholars in the London-based Bibliographical Society. The leaders in the group are often named almost as one individual: Alfred W. Pollard, W. W. Greg, and R. B. McKerrow. It was McKerrow who, with his textbook An Introduction to Bibliography for Literary Students (1927), was most responsible for disseminating the aims and techniques of the new...