Clairaut

Denis Diderot, of French encyclopedia fame, wrote that the geometer Alexis Clairaut had “overdosed on pleasure and women” and probably died of an excess of rich food.

Clairaut lived at a time “when every brilliant woman of the court and the city wanted a geometer in her collection.”

Her tutor in both is said to have been the famous mathematician Clairaut; and between them they rendered geometry so much the fashion at one time, that all the women, who were distinguished either for rank or beauty, thought it indispensable to have a geometrician in their train.

It follows from Clairaut’s theorem that if the earth is an oblate spheroid, its ellipticity can be determined from relative values of gravity and the absolute value at the equator involved in c.

Observations with nonreversible, invariable compound pendulums have contributed to the application of Clairaut’s theorem in its original and contemporary extended form for the determination of the figure and gravity field of the earth.