Brass surveying theodolite manufactured by W. & L.E. Gurley

This theodolite was manufactured by W. & L.E. Gurley, a prominent American company founded in 1845 in Troy, New York, that specialized in precision surveying instruments. Gurley instruments were widely used throughout the late 19th and 20th centuries for land surveying, construction, and engineering projects across North America. The design features the classic configuration with a horizontal circle, vertical arc, and telescope mounted on a tripod base. Surveying theodolites like this one played a crucial role in the development of American infrastructure, from railroad construction to urban planning and property boundary determination. These instruments are highly valued by collectors of scientific instruments, engineering enthusiasts, and historians focused on American technological development. Their precision craftsmanship and historical significance make them sought-after pieces that represent an important chapter in the history of land measurement and development.