Illustrations depicting strength and light.

Nikolaus Otto, German industrial inventor, invented the atmospheric gas engine.

In France, the scientist Marius-Paul Otto, after a thesis in physical sciences on ozone, started operating an experimental factory in Auteuil in 1899, and designed projects to purify the water in his native city, Nice. Sterilization, called "ozonization" (sometimes "ozonation" or "ozonification"), involves bringing water into contact with electrified air, which produces ozone (O3). Today the company is called Compagnie des Eaux Ozone, M POTTO Processes.