revision preference src: Who assisting the U.S. Weather Bureau in research, the USAAS Balloons and Airship School scheduled fifteen balloon flights from Scott Field, Illinois, for Dr. C. LeRoy Meisinger. Who had gained experience with balloons and meteorology as an Air Service officer during the war. <SEP> tgt: Assisting the U.S. Weather Bureau in research, the USAAS Balloons and Airship School schedules fifteen balloon flights from Scott Field, Illinois, for Dr. C. LeRoy Meisinger, who had gained experience with balloons and meteorology as an Air Service officer during the war.