Accession No

1149

Brief Description

sine/cosine calculator, in silver, purportedly by Johannes Bos, 1623, but actually a c. 1920 fake

Origin

Netherlands; Amsterdam [possible, see Price 1956]

Maker

fake, unknown maker Bos, Johannes [purported]

Class

horology; calculating

Earliest Date

1911

Latest Date

1925

Inscription Date

1623

Material

metal (silver); hide (leather)

Dimensions

case length 88mm; breadth 84mm; thickness 15mm

Special Collection

Provenance

Derek de Solla Price, as part of his research into possible fakes in the Whipple collection published in 1956, asserts that this is a copy of the original sine/cosine calculator sold in sale of Mensing Collection. Donated by Robert S. Whipple in 06/1952. Purchased by Robert S. Whipple from Antique Art Galleries, Grafton Street, London, in 06/1952.

Inscription

‘I BOS Ao 1623’

Description Notes

Sine/cosine calculator, in silver, fake, c. 1920, (purports to be by J. Bos, 1623).

Circles divided 1-12 twice by 1 to 15´and 0 - 360˚ by 10˚ and 1 - 9 twice, and the signs of the zodiac, 6 either side (next to numbers 8,9,1,11-16; 28-1-2000). Rotating volvelle with sun and moon index divided 1- 12.
Verso arc divided [0] - 90˚ by 10 to 1, and a diminishing scale along the bottom; sliding bar divided 0 - 90˚; table at one end.
Slip case.

Condition: good; complete.

[NOTE: On 15/04/2015 XRF analysis was conducted on this instrument. Results and analysis are given in the ‘Notes’ field.]

References

Events