Accession No

1779


Brief Description

napier’s bones, English, late 17th century


Origin

England


Maker


Class

mathematics; calculating


Earliest Date

1675


Latest Date

1700


Inscription Date


Material

ivory; metal


Dimensions

length 142mm; breadth 88mm; depth 23mm


Special Collection

Holden-White collection


Provenance

On loan from The Fitzwilliam Museum, University of Cambridge. Donated by Charles Holden-White to the Fitzwilliam Museum, 1931. C. Holden-White collection, no. 133.


Inscription


Description Notes

Ivory rods in ivory case with ivory tabulat. Case lacks lid. tabulat has lid at left hand calibrated as the multiplicand rod. 10 rods, with an additional rods for squares and cubes. Rods calibrated n all 4 faces, with the multiplication table from 1 - 9 reading from top to bottom. At the foot of the rod, are stamped the multiplicands for the 2 adjacent faces.

Incomplete (lid missing)


References

Mikey McGovern; 'John Napier's calculating tools'; Explore Whipple Collections online article; Whipple Museum of the History of Science; University of Cambridge: https://www.whipplemuseum.cam.ac.uk/explore-whipple-collections/calculating-devices/john-napiers-calculating-tools


Events

Description
In 1617 John Napier invented the calculating aid Napiers bones. These were first described in his book Numeration by Little Rods in 1617. Each of the 10 rods or ‘bones’ in a set are engraved with a multiplication table. This simple device made multiplying and dividing large numbers very easy by transforming the calculations into simple addition and subtraction. The rods became extremely popular and spread across Europe lasting well into the 20th century where they were still used in primary schools in the 1960s.

From display label:

Napier’s bones automate the use of logarithms for calculating. This set is arranged to show the calculation 2394 x 7. 2394 is arranged along the top row, and the answer is read by adding the values along row 7 (=16758).



FM:39541

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