Engraved portrait of Jean Errard.
Jean Errard was a French mathematician and military engineer. He was serving the King of France Henry IV. It is remembered for the volume "Des instruments mathématiques méchaniques", in which are explained with text and images various mechanical devices he invented..
Who-is-Who in MMS, History of machines, history of mechanical engineering, machine design, descriptive geometry, theory, engineer, architect, teacher, designer, inventor, treatizer.