discussed Cited "see" City of Durango v. Durango Transportation, Inc. See Louisville v. Babb, 75 F.2d 162, 166 (7th Cir.1935) (adopting the “broader meaning” of “municipal” of “public or governmental purpose as distinguished from private,” in construing constitutional authorization for property tax exemption), cert, denied, Babb v. Louisville, 295 U.S. 738 , 55 S.Ct. 650 , 79 L.Ed. 1686 (1935); St.