Accession No
2707
Brief Description
surveying instrument, by Laguna de Rins, Spanish, 1920 (c)
Origin
Spain; Zaragoza
Maker
Laguna de Rins
Class
surveying
Earliest Date
1920
Latest Date
1920
Inscription Date
Material
metal (bronze, brass, steel, silver); glass; plastic; wood
Dimensions
box height 437mm; breadth 317mm; depth 260mm height 1484; max diameter 70mm
Special Collection
Provenance
Purchased from Christie’s, South Kensington, London, England; lot 140, 8/1/1981.
Inscription
‘Laguna de Rins
ZARAGOZA
No 2065’ (on compass dial)
‘VDA DE AMADO LAGUNA DE RINS
Fabrica de Instrumentos de precision
ZARAGOZA’ (plate in box)
Description Notes
Bronze finish brass telescope; knurled brass screw operating rack and pinion focus on eyepiece. 1 vertical and 3 horizontal cross hairs. Lens cover. ‘Y’ mounts with eyepiece clipping into spring clips. Hinged retainers with spring clips. Eyepiece mounted on steel plate moving by means of rack and pinion between two graduated verticals. Graduations 26-0 on one side and 0-36 on other, by 2 to half where 4 equal 10mm. Read by vernier. Clamp. Pinhole and cross hair sights on uprights. Horizontal circle; silvered scale graduated 0-360 by 10 to 30’ read by vernier to 30” by plastic reflector and reading microscopes. Clamp and slow motion screw for vernier and horizontal circle. Compass over; graduated 0-360 by 10 to 30’. Half blued needle with clamp. 4 compass points. Long bubble over compass parallel with telescope axis graduated to 2mm. Tribach feet with levelling screws. Base plate. Steel plumb bob. Knurled brass key. Ray shade. Fitted wooden box. Tripod.
References
Events
Description
The Theodolite is a relatively, simple tool used for measuring angles, both horizontal and vertical. They work using the same principles as a protractor, the ‘point A’ is located and the angle noted, and then the telescope is pointed at ‘point B’ and the second angle is taken.
Although primarily used in surveying the theodolite can be applied to both Meteorology and Navigation.
Gemma Frisius proposed the idea behind the theodolite in 1533. At the time new methods of surveying were being used and by combining an Alidade, a magnetic compass and the degree scale on the back of an Astrolabe, the calculations made by modern theodolites could be observed. Unfortunately, this method was not practical due to the combination of instruments. The best of the attempts to simplify the process was the ‘theodolitus’, first described in print by Leonard Digges in 1571.
However, this instrument could only take measurements in the horizontal plane. Despite this it was still thought of as the ‘common’ Theodolite up to the late 18th century.
During the 19th century the Altazimuth Theodolite was considered the most useful theodolite, as it could measure on the horizontal and vertical planes. Three notable types of Altazimuth Theodolite were developed: The Everest Theodolite, the Plain Theodolite and the Transit Theodolite. It is the Transit Theodolite, which is still used today.
FM:43907
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