Niels Christensen

Niels Anton Christensen was a DanishAmerican inventor whose principal invention was the Oring, the ubiquitous hydraulic seal.

Niels Anton Christensen was born on a farm in TrringUldum Municipality, Denmark. He showed an early aptitude for mechanics and apprenticed to a machinist in Vejle, Denmark. After completing his apprenticeship, he entered the Technical Institute of Copenhagen, now the University of Copenhagen Faculty of Science. In 1891, Christensen immigrated to the United States when he wasyears old.

Source: Wikipedia