NAPIER, John (1550-1617).  Rabdologiae seu numerationis per virgulas libri duo.  Edinburgh: Andrew Hart, 1617.
NAPIER, John (1550-1617). Rabdologiae seu numerationis per virgulas libri duo. Edinburgh: Andrew Hart, 1617.

細節
NAPIER, John (1550-1617). Rabdologiae seu numerationis per virgulas libri duo. Edinburgh: Andrew Hart, 1617.

12/so (142 x 76 mm). 4 folding engraved tables, engraved and woodcut diagrams in text. (Short marginal wormtrack in quire C, small tear on one folding plate near gutter.) Contemporary vellum; cloth slipcase. Provenance: "S. Juliani ... Congr. S. Mauri catalogo inscriptus" (contemporary inscription on title-page); Felt & Tarrant Mfg. Co. (gift bookplate to); The John Crerar Library (small ink-lettered name on cover and shelf mark on spine).

FIRST EDITION. One of the earliest forms of mechanized calculation was presented in Napier's work entitled Rabdologiae, a term used to describe his invention of numeration by little rods of wood or ivory (known as "Napier's bones"). "Each of the ten rods had numbers inscribed in geometric squares which, in multiplication, were arranged by digit and the products recorded and added. Later the rods were mounted on a rotatable cylinder and an arrangement of these in a box constituted a calculator" (Dibner). Napier's work represents an attempt to devise more efficient ways of calculation by the use of rudimentary calculating devices. Other methods include the "aereal abacus," consisting of a checkerboard with counters expressing numbers in the binary scale, and the "promptuary" or "lightening calculator." This "deals with a more complicated system of multiplication by engraved rods and strips, which has been called the first attempt at the invention of a calculating machine" (DSB). VERY RARE. Dibner Heralds of Science 107; STC 18357; Norman 1574.