gradiometern.

1899 W. G. Bligh Notes Instruments Engin. Field-work v. 89 The ordinary type of level is always at a disadvantage when the ground is sloping. To overcome this difficulty..a variation has been made..which permits the telescope to be inclined. One of these is Stanley's Patent Gradiometer, an excellent combination of the level and clinometer.

1940 Chambers's Techn. Dict. 384/2 Gradiometer, an instrument for setting out long uniform gradients; it consists of a level that may be elevated or depressed, by known amounts, by means of a vertical tangent screw.

1960 H. L. Michael in K. B. Woods et al. Highway Engin. Handbk. ii. 11 Devices called ‘gradiometers’ or ‘inclinometers’, essentially bubble tubes graduated to read either percentage of grade or degree of incline, have been constructed to obtain grade information.

1929 Mining Mag. XL. 272 (heading) The gravity gradiometer.

1929 Mining Mag. XL. 277 On account of its small size and its rapid speed of operation the gradiometer is admirably adapted for use in confined spaces such as underground mine galleries.

1934 Trans. Amer. Inst. Mining & Metall. Engineers 110 383 At right angles to the magnetic meridian..a positive gradient implies that the vertical component of the magnetic field is increasing to the east. In the magnetic meridian, the effective component is that in the magnetic vertical plane through the center of the gradiometer.

1957 Encycl. Brit. X. 681/2 In a design by Shaw and E. Lancaster-Jones [of an instrument for the measurement of gravity gradients] the beam system is made irresponsive to ‘curvature’ effects and is called a gravity gradiometer.

1971 Sci. Amer. Aug. 70/2 During the time when the moon was inside this region of very steady magnetic fields we sent commands to the instrument that enabled it to function as a gradiometer.