Translation of "abney level" into French

A clinometer used to measure tree heights.Philip Babcock Gove (editor), Webster's Third International Dictionary of the English Language, Unabridged (G. & C. Merriam Co., 1976 [1909], ISBN 0-87779-101-5), page 4 [First attested in the late 19 ^th century.]Lesley Brown (editor), The Shorter Oxford English Dictionary, 5th edition (Oxford University Press, 2003 [1933], ISBN 978-0-19-860575-7), page 6 [..]