A franchise has been defined as the "grant of a right or privilege by the sovereign power usually with respect to streets or highways primarily to enable the grantee to perform a public service or benefit....", and that, "It is everywhere agreed that the right to lay pipes in the public highways is itself a franchise" [Johnson City v. Milligan Utility District, 276 S.W.2d 748 (Ct. App. 1954); Nashville Water Co. v Dunlap, 138 S.W.2d 424 (1940)]. It has also been expressly and impliedly held that a public utility must obtain a franchise to use a city's rights of way [Knoxville v. Park City, 130 Tenn. 626 (1914); Lewis v. Nashville Gas & Heating Co., 162 Tenn. 268 (Tenn. 1931); Franklin Light & Power Company v. Southern Cities Power Company; 47 S.W.2d 86 (Tenn. 1932); Holston River Electric Co. v. Hydro Electric Corp, 64 S.W.2d 509 (Tenn.1933); City of Chattanooga v. Tennessee Electric Power Co., 112 S.W.2d 385 (Tenn. 1938); Nashville Gas & Heating Co. v. City of Nashville, 152 S.W.2d 229 (Tenn. 1941); Patterson v. City of Chattanooga, 241 S.W.2d 291 (Tenn. 1951); Briley v. Cumberland Water Company, 389 S.W.2d 278 (Tenn. 1965)].