Mathematical Notes by Professor Tait (3.) On a Fundamental Principle in Statics

Extract

The principle that, while additional constraints cannot disturb equilibrium, unnecessary constraints may be removed without disturbing equilibrium, is of very great use in the statics of fluids and of elastic and flexible bodies. But it seems not to have been made use of to the extent its importance deserves.

My attention was recalled to it when attempting to compare the shares taken by gravity and cohesion in resisting the tendency of the so-called centrifugal force to split a planet. The problem which first proposed itself was to determine the gravitation attraction of one-half of a uniform sphere upon the other.