Jean-André Deluc or de Luc was a Swiss geologist, natural philosopher and meteorologist. He also devised measuring instruments.
Jean-André Deluc
Deluc's whalebone hygrometer, on display at the Musée d'histoire des sciences de la ville de Genève.
Introduction page of a 1772 copy of volumes 1 of "Recherches sur les modifications de l'atmosphère"
1772 copy of volumes 1 and 2 of "Recherches sur les modifications de l'atmosphère"
Georges-Louis Le Sage was a Genevan physicist and is most known for his theory of gravitation, for his invention of an electric telegraph and his anticipation of the kinetic theory of gases. He was a contributor to Diderot's Encyclopédie.
Georges-Louis Le Sage