Letter from the Secretary of War transmitting a letter from the Chief of Engineers, United States Army, dated October 31, 1946, submitting an interim report, together with accompanying papers and illustrations, on a preliminary examination and survey for flood control at the City of Tucson, Ariz., and vicinity, in accordance with the Flood Control Act approved on June 28, 1938, which authorizes a preliminary examination and survey of Gila River and tributaries, Arizona and New Mexico.