Napier's bones
Also Nepier's, Naper's.
[See def.]
Narrow slips of bone, ivory, wood, or other material, divided into compartments marked with certain digits, and used to facilitate the operations of multiplication and division according to a method invented by John Napier of Merchiston (1550–1617). Also occas. called Napier's rods.
The method was described by Napier in his book Rabdologiæ seu Numerationis per Virgulas libri duo (1615).
| a 1658 Cleveland On Ugly Woman 15 Who would suppose..That crookt et-cætera's were Wrinkles, and Five Napiers Bones glew'd to a Wrist, an Hand. 1664 Butler Hud. ii. iii. 1095 A moon-dial, with Napier's bones, And sev'ral constellation stones. 1678 Phillips, Nepiers Bones or Rods. 1727–38 Chambers Cycl. s.v. Neper's. 1834 Edin. Rev. LIX. 320 The method of calculation invented by Baron Napier,..since called Napier's bones. 1866 Chambers's Encycl. VI. 662/2 The contemporaneous invention of logarithms..caused Napier's bones to be overlooked, and they are now scarcely ever used. |