Fontaine was born in
Claveyson,
Dauphiné. He first got a taste for maths by reading the ''Géométrie de l'infini'' of
Fontenelle and gave solutions to the problems of the
tautochrone curve, the
brachistochrone curve and
orthogonal trajectories. He was elected a member of the
Académie des sciences in 1733. He died, aged 67, in
Cuiseaux. == Publications ==