a hand level for determining elevations and angles of slope.
British Dictionary definitions for Abney level
Abney level
/ˈæbnɪ/
noun
1.
a surveying instrument consisting of a spirit level and a sighting tube, used to measure the angle of inclination of a line from the observer to another point
Word Origin
C20: named after Sir William Abney (1843–1920), British chemist and physicist