  The main topic of this article is a discussion about the best way to show
students that the proportionality of mass and weight, strictly true for
point-like particles, is an excellent approximation for objects of "normal"
size. The usual way of addressing this issue, although very simple, is not
entirely satisfactory. Our approach considers first and second order,
coordinate dependent, gravimetric effects, connected to the internal geometry
of objects; these effects, extremely small, are estimated through examples.
