How is a tilting level used?

A tilting level is an optical surveying instrument used to measure vertical angles and determine differences in elevation between points. It consists of a telescope mounted on a base that can be tilted, allowing for precise leveling. Surveyors use it by sighting a leveling rod placed at a known distance, adjusting the tilt to ensure the crosshairs align with the rod's measurement, thereby calculating height differences accurately. This tool is essential in construction, land surveying, and civil engineering projects.