The quantity gc obtained by subtracting from a gravity anomaly Δg the following gravity corrections: (a) the condensation gravity correction &3948;g _c; (b) the free air gravity correction δg _f; and (c) a Bouguer gravity correction δg _B, a modified Bouguer gravity correction δg _Bm or an expanded Bouguer gravity correction δg _BE. Applying the condensation gravity correction is the mathematical analog of replacing all the mass between the reference surface and an equipotential surface through the point P at which gravity was measured by a thin layer of mass condensed onto the reference surface (or at a predetermined distance below it). Applying the free air gravity correction then changes gravity from its value on the reference surface to the corresponding value at elevation Hp, and applying the Bouguer gravity correction replaces the missing mass by the Bouguer plate or some modification thereof. If the distance (called the depth of condensation) of the layer of condensed matter below the reference surface is zero, i.e., if the mass is applied as a coating to the reference surface, the gravity anomaly is sometimes referred to as Faye's gravity anomaly, because Faye proposed putting the layer on the reference surface. However, because the term Faye's gravity anomaly has also been used for other kinds of gravity anomaly, the term is best not used at all. Note that to some extent, depending on how the mass to be condensed is estimated and on what kind of Bouguer correction is applied, the condensation gravity is a variant of the Bouguer gravity anomaly with topographic correction.