Accession No
2384
Brief Description
napier’s bones, slip-form, English, circa 1690
Origin
England
Maker
Class
mathematics; calculating
Earliest Date
1690
Latest Date
1690
Inscription Date
Material
wood (boxwood); metal (brass)
Dimensions
length 100mm; breadth 60mm; thickness 19mm
Special Collection
Provenance
Purchased from Christie’s, 8 King Street, St James’s, London, 19/07/1978. Purchased with the assistance of a Grant-in-Aid from the Science Museum (PRISM).
Inscription
Description Notes
45 Napier’s rods in case, edges decorated with inscribed parallel lines, faces with similar border and decorative motifs built up from lines, squares, circles and arcs of circles. Push-fit top reveals compartment for tabulat and 5 compartments for the lamina form rods. Compartments are numbered ‘09’, ‘18’, ‘27’, ‘36’ and ‘45’ and each will hold 9 rods. The rods are calibrated on each face with the multiplication table of 2 - 9 of a digit. (One of the 3/6 rods missing.) The compartment 0/9 has an enlarged slot to take a rod with table of squares and cubes.
Condition good; incomplete (one rod missing)
References
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.
FM:39544
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