On the addition of velocities in relativity theory A. Sommerfeld

Presented in translation from the German is A. Sommerfeld's paper “Über die Zusammensetzung der Geschwindigkeiten in der Relativtheorie”, Physikalische Zeitschrifl 10 826 (1909), which retains its relevance a hundred years after its publication, as is discussed by G. В. Malykin, Usp. Fiz. Nauk 180 965 (2010) [Physics-Uspekhi 53 (9) (2010)].