Karl Freiherr von Drais (full name: Karl Friedrich Christian Ludwig Freiherr Drais von Sauerbronn; 29 April 1785 – 10 December 1851) was a noble German forest official and significant inventor in the Biedermeier period. He was born and died in Karlsruhe. He is seen as "the father of the bicycle".
Nicolaus August Otto (10 June 1832, Holzhausen an der Haide, Nassau – 26 January 1891, Cologne) was a German engineer who successfully developed the compressed charge internal combustion engine which ran on petroleum gas and led to the modern internal combustion engine. The Association of German Engineers (VDI) created DIN standard 1940 which says "Otto Engine: internal combustion engine in which the ignition of the compressed fuel-air mixture is initiated by a timed spark", which has been applied to all engines of this type since.