Culvertons has dated this Antique Brass Vernier Theodolite to the 1880s.
The significance of this signature only became apparent after some research. This vernier theodolite appears to have belonged to the celebrated English civil engineer John Frederick Bateman.

[Wikipedia .... John Frederick La Trobe Bateman FRSE FRS MICE FRGS FGS FSA (30 May 1810 – 10 June 1889) was an English civil engineer whose work formed the basis of the modern United Kingdom water supply industry. For more than 50 years from 1835, he designed and constructed reservoirs and waterworks. His largest project was the Longdendale Chain system that supplied Manchester with much of its water since the 19th century. The construction of what was in its day the largest chain of reservoirs in the world began in 1848 and was completed in 1877. Bateman became "the greatest dam-builder of his generation". Bateman also worked on water supply systems for Glasgow, Belfast, Bolton, Chester, Dublin, Newcastle upon Tyne, Oldham, Perth, Stockport and Wolverhampton, amongst many others. He carried out projects abroad as well, including designing and constructing a drainage and water supply system for Buenos Aires, and water supply schemes for Naples, Constantinople and Colombo. He was President of the Institution of Civil Engineers in Britain in 1878 and 1879. In 1883, Bateman assumed his mother's family surname of La Trobe, by royal licence, becoming John Frederic La Trobe Bateman.] For more information please visit https://en.wikipedia.org/wiki/John_Frederick_Bateman

As you can see from the images, it has its original tripod, plus another base that enables it to be easily displayed on a surface whilst it's detached from the tripod (this was cleverly designed and engineered by the previous owner). When attached to the tripod its average overall height when open is 140 cm.
Culvertons has dated this Antique Brass Vernier Theodolite to the 1880s.
You can view the stock and full dealer information on the Culvertons Profile Page