Accession No

1587

Brief Description

abacus and base for Napier’s bones (part of the ‘Instrument for Arithmeticke’), by Robert Jole, English, 1667 - 1700

Origin

England; London

Maker

Jole, Robert

Class

mathematics; calculating

Earliest Date

1667

Latest Date

1700

Inscription Date

Material

wood (boxwood); glass; metal (steel, brass, silver)

Dimensions

length 205mm; breadth 58mm ; thickness 24mm; length of cursor 185mm

Special Collection

Provenance

Purchased. Purchased by previous owner from Sotheby’s on 27/10/1969, lot 6.

Inscription

‘C C
Robert Jole fecit ‘ (on reverse)

Description Notes

Abacus forming lid of Sir Charles Cotterell’s Instrument for Arithmeticke. Inside of lid formed as counting board, 16 wires, each with 4 black, 1 white and 4 black glass beads (one alternate black and white) (some black beads missing). Lip marked right to left ‘I’, ‘X’, ‘C’, ‘M’, ‘X’, ‘C’, ‘MM’ .... 1015 with pricking off holes. When inverted the other lip is marked right to left ‘I’ , ‘XI’, ‘XI’, ‘I’, ‘X’, ‘C’, ‘M’, ‘X’, ‘C’, ‘MM’, ‘X’, ‘C’, ‘M’, ‘X’. Base acts as a tablet for strip form Napier’s bones (all missing). At the left edge a bevelled slope calibrated 1 - 9 by 1 with 2 pricking off holes and marked ‘The Index of ye Quotient’. The left edge similarly calibrated and marked ‘The Index of ye Multiplier’. top lip marked ‘Divisor’ and ‘Multiplicand’. Bottom lip from right to left ‘I’, ‘X’, ‘C’, ‘M’... to 10 15. In the base is a paper table ‘The Fore Rule’ and ‘The Backe Rule’ printed from an engraved plate. All marking on the boxwood from metal punches. Silvered brass pierced cursor for reading the bones.

Condition fair; incomplete (bones and some of the beads missing)

References

Events