the world > the earth > earth sciences > geography > map-making > surveying > [noun] > surveying instruments > for measuring inclination or gradient (5)
An instrument for ascertaining the position of a line or plane with reference to its azimuth and altitude; a declinator.
an instrument for indicating the inclination of a surveyor's chain.
a small hand-held instrument used in surveying for the measurement of slopes and vertical angles, invented by Abney in the 1870s.
Any of various surveying instruments used for setting out gradients or for measuring the gradient of a slope (see quots.).