The Crooked Hinge

A Harper copyright page without the 'FIRST EDITION' line, or carrying a code other than I-N, is a later printing. Beware Harper's year-letter recycling: Harper began reusing year letters in 1937 on a 25-letter cycle (J omitted), so I-N can in principle also read September 1963 — the 1938 book is separated by its period binding, paper and jacket design, and by the Harper & Brothers imprint itself (the firm became Harper & Row in 1962). The 1957 Harper omnibus 'John Dickson Carr Trio' (LCCN 56008777), the University of California Extension issue (1976, LCCN 76056880), Collier Books (1984, LCCN 84005016) and Penzler Publishers (2019) are reprints.