Accession No

1857

Brief Description

gunner’s callipers by Gilkerson, c.1825

Origin

Tower Hill; London; England

Maker

Gilkerson

Class

military

Earliest Date

1825

Latest Date

1825

Inscription Date

Material

metal (brass, steel)

Dimensions

length closed 174mm; breadth 43mm; thickness 12mm

Special Collection

Heywood collection

Provenance

Purchased from the Professor Harold Heywood collection under estate duty exemption benefit with the assistance of a Science Museum PRISM grant-in-aid.

Inscription

‘Gilkerson Tower=Hill LONDON’ (obverse)

Description Notes

Brass six-inch radius callipers with inset steel points.
Obverse: limb A divided [0] - 6 inches, numbered by 1, subdivided to 0.1. Table of ‘Quantity of Powder for filling the Chambers of Brass Mortars & Howitzers’ with values given for both sea and land. Round hinge circular sector scale ‘shot’ 1/2 - 42 numbered 1/2, 1, 11/2, 3, 4, 6, 9, 12, 18, 24, 32, 42 for weight of iron shot with index on limb B. Limb B has continuation of scale of inches [6] - [12], numbered by 1, subdivided to 0.1. Pair of scales to measure internal bore. ‘Inches’ divided [2] - 8, numbered by 1, subdivided to 0.2 and corresponding scale ‘Guns’ divided 1.5 - 42 numbered 11/2 , 3, 4, 6, 9, 12, 18, 24, 32, 42 to give normal weight of shot. Semicircular scale 0 - 180˚, numbered by 10˚, subdivided to 2˚, and 180˚ - 0, numbered by 10˚. Circular sector scale for diameters of shot 0 - 8 ‘Inches’, numbered by 1, subdivided to 0.2.
Reverse: limb B has Table for Quantity of powder for ‘Proof’ and ‘Service’ of ‘Brass Guns’; both limbs have sectorial line of ‘Lin’ divided [0] -10, numbered by 1, subdivided to 0.05. Limb A has Table for quantity of powder for ‘Proof’ and ‘Service’ of ‘Iron Guns’.
Fitted wooden case covered in red leather and lined with velvet; hook fastenings.

Condition good; complete

References

Events