Optical balance level, after a type used in the 17th Century, British, 1700-1799 Optical balance level 1700-1799
12-inch level by Troughton and Simms. With tripod. 12-inch level by Troughton and Simms. With tripod 1801-1900
Bubble level for checking the horizontality of telescope axis, early 19th century Bubble level for checking the horizontality of telescope axis 1801-1850
Level by Hall Brothers of Croydon, no.451232, HO 20, with tripod HO 19. In wooden case, c. 1940s Level by Hall Brothers of Croydon 1941-1950
Watkin's Improved Combined Finder, Level and Telemeter Watkin's Improved Combined Finder, Level and Telemeter
30 inch level by Cary, c.1830, used by J.A. Lloyd in 1831 to ascertain the fall of the Thames between London Bridge and Sheerness 30 inch level by Cary 1830