John Napier

“ The signatures in the editions described consist of the letters of the alphabet excluding J, U, and W, or 23 letters (in one or two instances J and U are used for I and V) . To each letter belongs a bundle of leaves, 4, 8, 12, &c., as the case may be. The leaves in each bundle are usually numbered thus :—C, C2, C3, etc., but frequently the signatures are printed only on the first one or two leaves in each bundle. The signature is very rarely printed on a title-page. When a leaf is described as B3, for instance, both sides are included, B31 being used to signify the recto and B32 the verso. ”

“ The symbols 4°, 8°, 12°, etc., indicate the number of leaves into which the sheet of paper was folded; but the number of leaves made up in the signatures sometimes differs from this: thus, for example, in the early editions of A Plaine Discovery, though the sheet is folded into 4 there are 8 leaves to each signature. ”

“ These works naturally fall into three groups: the first contains the result of his early studies in Revelation by which he became famous among the Reformed Churches of Europe, as one of the most learned Theologians of the day; another contains his works on Logarithms, by which his fame as a Mathematician was established in the scientific world; between these two groups may be placed his other works, which were more or less preparatory to or suggested during the elaboration of his Logarithms. Accordingly, in the Catalogue we have arranged his works in the following order: I. A Plaine Discovery ”