Accession No
2169
Brief Description
Bridge-Lee’s patent photo theodolite, by J. H. Steward, English, 1900 (c)
Origin
England; London; 406 Strand
Maker
J. H. Steward
Class
surveying
Earliest Date
1900
Latest Date
1900
Inscription Date
Material
metal (brass, oxidized brass, aluminium, white metal); wood; glass; hide (leather); cloth (velvet, felt); organic (hair)
Dimensions
height 347mm; depth 220mm; breadth 200mm; box length 550mm; breadth 245mm; height 237mm
Special Collection
Provenance
Transferred from Department of Geography, University of Cambridge, Cambridge, England, 05/1969.
Inscription
‘BRIDGES-LEE’S
PATENT
PHOTO THEODOLITE
J.H. STEWARD, 406 Strand, LONDON.
No. 24.’ (front of camera)
Description Notes
Bridge-Lee’s Patent Photo Theodolite, by Steward, c. 1900.
Telescope mounted on’A’ frames on top of camera. Inverting eyepiece. Rack and pinion screw moves objective. Vertical semi-circle with brass scale divided [49] - 0 - [98] numbered by 10 subdivided to 30’ read by vernier and magnifying glass to 1’ of arc. Clamp and motion screws for vertical motion. 2 bubbles mounted on top of camera. Aluminium camera box fixed to vernier plate. Brass lens mount with stops f8 - f64. Velvet lined, leather lens cap. Back of camera slides on twin rack and pinions. Internal compass scale divided 0 - [360] numbered by 5 subdivided to 30’. Ground glass back in wooden frame on double hinged brackets. Base of box has guides for plates which then clip into top. Horizontal circle with brass scale divided [0] - 360 numbered by 10 subdivded to 30’. Vernier reads scale to 1’. Magnifying glass for vernier. Clamp and motion screws for horizontal circle and vernier plate. 3 levelling screws on tribrach limbs clamped to trivet plate with central thread for attachment to tripod. Fitted wooden box. Erecting lens. 7 double-sided mahogany cased plates with slide. Trivet base for attachment to tripod.
Procedure for removing glass: Depress black metal release at top of box - releases metal pin which holds in wood frame. This will drop down wood frame holding glass, be ready to catch it. Glass can be removed from the wood frame by turning the four brass levers, but will not come out without dropping the wood frame first as it is snug. Ease it out carefully as the glass has been previously been repaired.
References
Events
Description
The Theodolite is a relatively, simple tool used for measuring angles, both horizontal and vertical.
In this instrument, the camera is mounted on a theodolite base on which it can rotate. There are levels and a telescope above the camera box. The photograph taken includes the compass bearing, reference cross-lines and various scales, as an aid to map-making. It was designed by James Bridges-Lee in 1894, and underwent later modifications by the inventor and his various manufacturers. This example was made by J.H. Steward around 1900.
10/03/2009
Created by: Dr. Anita McConnell on 10/03/2009
FM:40197
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