Complex sentence: Achille-Nicolas Isnard (Paris, 1748-Lyon, 1803) was a French economist and engineer, at the Ponts et Chaussées (public works) of Paris.
Split into simpler sentences: Achille-Nicolas Isnard (Paris, 1748-Lyon, 1803) was a French economist and engineer. He was employed as engineer at the Ponts et Chaussées (public works) of Paris.