No skating rink or skating room shall be erected, set up, kept or in any respect whatever used for the purpose of public entertainment within the city for gain to the owners or keepers thereof unless a license for that purpose is first obtained from the city treasurer. The fee for such license shall be twenty-five dollars per annum, payable quarterly in advance, and the license shall be issued only for the time paid for in advance. (Code 1953, § 14.6.)