Accession No

3244

Brief Description

four-prism brass table spectrometer, by John Browning, English, 4/4 19th Century

Origin

England

Maker

Browning, John

Class

optical

Earliest Date

1875

Latest Date

1900

Inscription Date

Material

metal (brass, oxidized brass); glass; wood (mahogany); cloth (felt)

Dimensions

partially open length 600mm; breadth 550mm; height 330mm; box breadth 460mm; height 433mm; depth 355mm

Special Collection

Provenance

Donated by Portsmouth City Museums, Museum Road, Old Portsmouth, Hants, England, 08/1985.

Inscription

‘John Browning London’ (on stage)
‘Browning
Spectroscope. ‘ (painted on box)

Description Notes

Four-prism brass table spectrometer, by John Browning, English, 4/4 C19th.

Brass collimator tube with slit. Slit has brass jaws adjustable by screw divided 0 - [10] and a reflecting prism on pivotted arm. Push-fit cover for slit. Collimator tube screws into mount on stand. Mount rotates (clamping screw missing). Collimator tube mount pivots on arm about centre of stand and is linked to prism train. Collimater arm motion controlled by clamp and tangent screw, with scale divided 0 - [100] and counter with scale divided 0 - [10] (increments by one for each complete revolution of micrometer dial). Prisms held on stage by screws on oxidized brass mounts. Telescope with rack and pinion focus screws into rotating mount (very stiff) which rotates on arm about centre of stand. Clamping screw for moun rotation and rotation about centre. Brass pillar stand sith flat tribrach limbs and 3 brass feet secured to wooden base. Wooden base slides out of fitted wooden box with brass hinges, lock and twin carrying handles. Box partially lined with green felt. Box also contains 2 spare screw-in eyepieces (stored on tubes) and 2 other lenses (purpose unknown); a ‘hollow-square’ key with milled head; 2 brass discs (for holding prism?); and 2 triangular pieces of felt for lining prisms in mount.

Condition good (slight corrosion on telescope near mount); incomplete (prisms missing)

References

Events