The Manager shall have general supervision over all corporations operating under franchises or privileges granted them by the City, and shall at least once in each year demand and receive reports from all such corporations, covering the condition of the business, the gross earnings, the net earnings and the extent to which the franchise of such corporation is being exercised, and shall have the right to appoint one (1) or more persons to inspect the books and property of said corporation, for such purposes and to verify such reports; and any such failure to make such reports when demanded, or to permit such inspection, shall be ground, at the option of the Council, for the forfeiture of such franchise or privilege.