Muscle Shoals: Hearings Before the Committee on Agriculture and Forestry, United States Senate, Sixty-seventh Congress, Second Session, on S. 3420, to Provide for the Manufacture of Explosives for the Use of the Army and Navy, to Provide for the Manufacture of Fertilizer for Agricultural Purposes, to Incorporate The Federal Chemical Corporation, and for Other Purposes; and on the Henry Ford Muscle Shoals Offer