Accession No

0337

Brief Description

parallel rule, by William Harris, English, 1825 (c)

Origin

England; London; 50 Holborn

Maker

Harris, William

Class

drawing

Earliest Date

1825

Latest Date

1825

Inscription Date

Material

metal (brass, steel)

Dimensions

Special Collection

Robert Whipple collection

Provenance

Purchased from Antique Art Galleries, London, on 20/01/1928.

Inscription

‘Harris 50 Holborn LONDON’

Description Notes

Double sliding bar rule. Pierced hinges knob in centre of each bar. [One screw missing and steel replacement]

good condition

References

Events

Description
Parallel rule
Used by architects, engineers, cartographers and on nautical charts, the parallel rule is used for drawing parallel lines accurately. It is also used in conjunction with a scale rule for producing orthogonal drawings (with lines in non-parallel direction as well). The pivoting links can be extended to the required distance, but this makes the instrument liable to error for larger drawings because the extension is changed by hand, and can be varied accidentally.

18/10/2002
Created by: Saffron Clackson on 18/10/2002

FM:39862