On the mechanism of the drag a moving body experiences in a fluid

Theodore von Kármán's original two papers on the vortex street, written in Germa, are presented in the English translation. Both papers appeared under the same title “Über den Mechanismus des Widerstandes, denein bewegter Körper in einer Flüssigkeit erfährt“ 14 September and 23 December 1911. To the author's knowledge the papers were never translated into English. Following a request of the editor Professor Max Platzer, their translation is given in the following.