On: “Gravitational Attraction of a Circular Disc,” by Shri Krishna Singh (GEOPHYSICS, Feb. 1977, p. 111–113)

It is unfortunate that in the Short Note no mention whatever is made of Nettleton’s classic paper on the subject: “Gravity and Magnetic Calculations”. (Geophysics, 1942, p. 308). Not only did Nettleton’s paper precede Singh by 35 years but it provides a more practical approach (stacked discs) to solving a difficult three‐dimensional problem. Nettleton’s method endured long and well until modern computers rendered it less efficient several years ago; his technique has been applied countless times to thousands of salt dome and mineral resource problems.