Onésiphore Pecqueur (1792-1852) was a French mechanical engineer, head of the workshops of the National Conservatory of Arts and Crafts, passionate about mathematics and master watchmaker1. In 1825, he invented a rotary steam engine, which he perfected until 18402.

in 1827, he invented the mechanical differential allowing the speed of the wheels to be adapted when cornering, with the less loaded wheel turning faster1.

In 1829, he patented a steam carriage intended to travel on the road, containing "most of the components capable of making it a good self-propelled vehicle