Gravity Instruments
Gravity instruments are those used in determining the size and shape of the Earth. They have become one of the most useful tools in geophysical prospecting and in geological studies. (Hoskinson 1936)
Sources
Hoskinson, Albert J. 1936. “Recent Developments in Gravity-Instruments.” Transactions, American Geophysical Union 17 (1): 44. https://doi.org/10.1029/TR017i001p00044.