Sir Thomas Malory's Le Morte Darthur was printed in 1485 by William Caxton the first printer in England. Between then and 1634 five subsequent editions were reprinted, but there followed a long hiatus between the 1634 edition by William Stansby and its reprinting in 1816. Interestingly, not one but two editions were published almost simultaneously in 1816 ; the first to appear was the Walker edition, and the second the Wilks edition. A "mystery" has surrounded the publication of these two editions ; Joseph Haslewood, the editor of the Wilks edition, complained in the Advertisement that it was only after his edition had entered the printing process that some other publisher, trying to forestall him, began printing a rival edition of Malory. In order to verify the validity of Haslewood's claim, i.e. to ascertain whether a printing that was started earlier could have been overtaken by a rival edition, it is vital to determine the format of each edition, from which it is possible to calculate the time of imposition and printing.
Both of these editions, so similar in size (small pocket size) and engraved vignettes, tend to be regarded as having been printed in the same format. The British Library catalogue, for example, records both editions as 12° (duodecimo), whereas nineteenth-century editors list them variously as 12° or 24° (twenty-fourmo). The present paper, which includes photographic images, provides a record of an anatomical examination of a copy of the Walker edition, and concludes that the Walker edition is of the format described by Philip Gaskell, i.e. "Two half-sheets of twenty-fours, imposed the sixteen way and worked together (24° in 12s the 16 way, 2 sigs.)," and that theoretically, the choice of this format enabled the Walker edition to be published earlier than the Wilks edition.