Barometers, 1772.

Engraved plate by G Dheulland from 'Recherches sur les Modifications de L'Atmosphere', (1772) by Jean Andre Deluc, after a drawing by the author. Deluc (1727-1817) was a Swis geologist, meteorologist and physicist, born in Geneva. He tried to prove that creation as described in the Bible was consistent with science. He investigated the atmosphere and the density of water, invented a hygrometer and and was the first to record accurately the heights of mountains by using a barometer.