Theodolite
The theodolite is an instrument that is used in surveying. The origin of the theodolite is unknown but it has been traced back to 16th century English mathematician Leonard Digges. The theodolite measures vertical and horizontal angles.
The theodolite has changed over time. In its current form it is a telescope mounted to swivel both horizontally and vertically. The theodolite is used to find angles in road building, tunnel alignment, and other civil-engineering work. There are also many various forms of the theodolite today.