University of Virginia Library

Twenty-Fours with Three Signatures
by
Kenneth Povey

Dr Curt Bühler's account of the imposition of an edition of Valerius Maximus dated Amsterdam, 1671 and probably printed by Johann Blaeu should have a much wider usefulness than he claims for it.[1] 24mos in threes 'the sixteen way' must be fairly common if one may judge from their inclusion in text-books, but no doubt they have often been recorded as 16mos, a mistake easily made since the chainlines in both formats are horizontal unless the printer used half sheets of double paper or paper made two sheets at a time on broad double moulds. The incidence of the watermarks should give warning of the ternary imposition.

Dr Bühler's example is of the standard two squares and an oblong type, with the square sections imposed as octavos, but all three sections could be oblong. It is to be found in Georg Wolffger's New-Auffgesetztes Format-Büchlein, Graz, 1672,[2] and I represent it in diagram 1. (All my diagrams, following Dr Bühler's convenient precedent, show the positions of the pages in the sheet and not, as the text-books show them, in the forme.) Diagram 2, from M. D. Fertel, La science pratique de l'imprimerie, Saint Omer, 1723, pp. 166-167, is the same as 1 except that the inner forme of B is imposed with the outer forme of A. In diagram 3, from J. G. Ernesti, Die wol-eingerichtete Buchdruckerey, 2nd ed., Nürnberg, 1733, pp. 96-97, section B is turned round so that leaves 1 and 3 change places. Here too the inner forme of B could be imposed with the outer forme of A, making a second pair of variants like the Wolffger-Fertel one, and in that case B1v would occupy the position of B2v in the diagram. Thus A1 at the corner of the sheet may be accompanied by B1 at top left (Wolffger), top right (Fertel), bottom right (Ernesti) or bottom left (postulated). Section C is the same in Wolffger, Fertel and Ernesti, but it could theoretically, and rather improbably, undergo the four mutations of B in relation to A, and any of its four states could be combined with any of the A-B combinations. Fertel, it may be noted, instructs the binder to fold section C twice from end to end and once down the middle — Dr Bühler is mistaken in supposing that it has to be cut.

Diagram 4 represents another imposition of section C diagnosed by Mr I. J. C. Foster and myself in Jacobus Hautinus, Angelus custos, Antverpiæ,

J. Cnobbaert, 1636, from the copy in the University Library, Durham. Sections A and B are as in Wolffger, proved by the occurrence of watermarks across the fold near the head of 2-7 in most A sections and of 1-8 in some B sections. In this and in the partly uncut and unopened copy in the Bodleian Library, all the C sections have been folded as required for the Wolffger-Fertel-Ernesti imposition, so that the order of the leaves is 1,4,3,2, 7,6,5,8, suggesting that that imposition was the one most familiar to the binder. With Cnobbaert's imposition it is necessary to begin by folding ends to middle.

Notes