The U.S. Army became interested in ballooning and purchased two hydrogen balloons. One of these made a flight from Washington, D.C., to Harrisburg, Pennsylvania, on June 4, 1907. The Army observer on this flight was Capt. Charles deForest Chandler. Ballooning activities increased significantly during the following months as Army personnel gained aeronautical experience. On August 1, 1907, the Aeronautical Division was established within the Signal Corps of the U.S. Army, with Capt. Chandler placed in charge. This embryonic organization was the forerunner of the United States Air Force. Within six months, a dirigible was ordered for this new component.