Napier's bones

American  

noun

(used with a singular verb)

1. a form of multiplication table originally marked on sticks of bone or ivory that could be rearranged to carry out the operations of multiplication or division.

---

Napier's bones British  

plural noun

1. a set of graduated rods formerly used for multiplication and division

---

Etymology

Origin of Napier's bones

First recorded in 1650–60; after their developer, J. Napier

Example Sentences

Napier’s bones - a device to facilitate calculation invented by John Napier in the seventeenth century - are now unbreakable.

From The Guardian

In Hudibras: "A moon-dial, with Napier's bones, And several constellation stones."

From Project Gutenberg

Step by step improvements were made; the most important being that invented by Napier of Merchiston, the inventor of logarithms, commonly called Napier's bones, consisting of a number of rods divided into ten equal squares and numbered, so that the whole when placed together formed the common multiplication table.

From Project Gutenberg

It would perhaps be rank heresy to suppose that Sir Walter did not know that ``Napier's bones'' were an apparatus for purposes of calculation, but he certainly puts the expression in such an ambiguous form that many of his readers are likely to suppose that the actual bones of Napier's body were intended.

From Project Gutenberg

Goldsmith—French memoir writers— Historians—Napier's bones—Mr. Gladstone— Lord Macaulay—Newspaper writers—Critics .

From Project Gutenberg