Columbia University's Rare Book and Manuscript Library recently acquired Baguettes de Nepper, auteur des tables des logarithmes, an unpublished 17th-century French manuscript on the construction and use of ‘Napier’s bones’ (or ‘rods’), the innovative calculating device invented by the Scottish mathematician John Napier (1550-1617) and first introduced in his Latin Rabdologiae in 1617. The Rabdologiae soon appeared in several European vernaculars, but it was not translated into French during the 17th century, making the present French-language manuscript ‘manual’ an intriguing witness to how knowledge of the Napier’s bones was disseminated in France among those who valued the device as an aide to practical arithmetical calculation but who did not have the leisure, patience, means or learning to confront Napier’s Latin text. While practical guides to the device in French were available in a handful of publications (e.g., the very rare Nouvelle invention d’apprendre l’arithmetique par le moyen de dix petits bastons by Jean Gallé [Paris, 1635]), it is likely that many who wanted an introduction to the functions of Napier’s bones gained it by reference to brief, straightforward digests like this manuscript.
Preserved in its original stab-stitched paper wrappers, the manuscript eschews all niceties about the history of Napier’s bones or the author’s biography, referring to Napier only as “the author of the logarithm tables” before neatly discussing how to lay out and use the device. A folding leaf depicting the faces of the rods is keyed with letters to the text, where multiplication, division, and the extraction of square and cube roots are treated; further folding leaves are added so that long calculations can be seen at a glance in their entirety.
John Napier “is best known for his invention of logarithms, but he spent a large part of his life devising various other schemes, both mechanical devices and logistical practices, for easing the labor involved in doing arithmetic … Napier did not at first consider these inventions worthy of publication; however, several friends, particularly Alexander Seton, the Earl of Dumfermline and High Chancellor of Scotland, pressed him to write them up, if only to avoid having others claiming them as their own. His descriptions appeared in a small book entitled Rabdologia in the year of his death and three years after his publication of logarithms … The use of Napier’s bones spread rapidly, and within a few years examples could be found in use from Europe to China. It is likely the two Jesuits Gaspar Schott and Athanasius Kircher were partially responsible for this dissemination, particularly to China” (Tomash & Williams, vol. 3, pp. 1451-3). The present manuscript, whether originally intended for use at home or abroad, reflects the popularity of Napier’s invention and represents an unusual survival of ephemeral pedagogical material of this sort.
The paper of the manuscript carries a watermark of the arms of Colbert that suggests that it was written out circa 1690 (cf. Heawood 690 and 694, both dated late-1680s).
* E. Tomash & M. R. Williams, The Erwin Tomash Library on the History of Computing, vol. 2, p. 920, no. N11; E. Heawood, Watermarks Mainly from the 17th and 18th Centuries.