Annamites at an airfield base

Mobilized on August 3, Friesz was ranked in the auxiliary service in November 1914 for health reasons, before being assigned to the 5th Bureau in August 1915. At the end of his convalescence, after trying in vain to convince the Press House to entrust him with the task of creating a summary of the crimes committed by the Germans, to be distributed in the United States and other neutral nations, in 1916, Friesz was assigned to the aeronautical technical service, where he worked in topography. As part of the airship observation team, in June 1917, he received several study missions, tasking him with creating a documentary museum on military aviation. In his work, he depicted the labor of the workers and prisoners as they constructed temporary structures for airfield bases, along with the Annamite and Tunisian mechanics.