Accession No


Brief Description

portable transit instrument, Russian-type, by T. Cooke and Sons, English, 1869


England; York


T. Cooke and Sons


astronomy; surveying

Earliest Date

Jan. 1, 1869

Latest Date

Dec. 31, 1869

Inscription Date


metal (cast iron, brass, other(?)); wood; cloth (velvet)


Special Collection


Transferred from Sedgwick Museum of Earth Sciences, University of Cambridge, 03/2015. Object was previously owned by the Sedgwick Museum of Earth Sciences and was on long-term loan at the Science Museum before ownership was transferred to the Whipple Museum in March 2015.


On box lid:
On side of both boxes:
BY T. COOKE AND SONS’ (printed paper label)
On instrument:
"T. Cooke & Sons
York & London"

Description Notes

Portable transit instrument, 'Russian'-type, by T. Cooke & Sons, English, c. 1869.

One of two "Russian" transit instruments ordered for the Great Trigonometrical Survey of India in 1869 (the other instrument is also in our collection, T197, T198, T804). The instrument is contained within in two boxes, made by T. Cooke & Sons. Large cast iron and brass transit instrument in two packing crates. First box contains cast iron base. Second, larger, wooden box contains transit instrument in case with wooden fixtures, lens cap and three loose bolts in the bottom of the box.

Instrument and mount is in good condition, box is in fair condition.

[Note: This is instrument "No. 1" of a pair - see also T804 / T197 / T198.]


Joshua Nall; ‘Survey Instruments in India’; Explore Whipple Collections online article; Whipple Museum of the History of Science; University of Cambridge; 2020:


This transit instrument, made in 1869 by Thomas Cooke and Sons, was used in the Great Trigonometrical Survey of India, which began in 1802 under the direction of the East India Trading Company and continued for more than 70 years. The instrument is one of two that could determine local time from the motion of the stars. This could then be compared with Greenwich time transmitted via telegraph, the time difference giving the site’s longitude. Once the telegraph lines were completed, this enabled surveyors to measure the absolute difference of longitude between Karachi and Greenwich, and thus would enable every point in India to be fixed by the survey.
Created by: Rosanna Evans on 29/09/2017


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