After the term of the present marshal of police shall expire by limitation or death, the office shall cease, and all the powers in him vested, not subordinate to the mayor, shall thereupon become vested in the mayor, and all his duties subordinate to the mayor shall be performed by a superintendent of police to be appointed by the director with the approval of the select council, subject to be dismissed by him, who shall receive such salary and perform such further duties as may be prescribed by ordinance.
53 P.S. § 16288