§ 135. Membership. No person shall be appointed to membership in the police or fire departments of the city, or continue to hold membership therein, who is not a citizen of good moral character, who has ever been convicted of a felony, who can not understandingly read and write the English language, and who shall not have resided in the city during the two years next preceding his appointment. The commissioner shall make all appointments, promotions and changes of status of the officers and members of the police and fire departments in accordance with the provisions of the civil service law of the state, except as otherwise provided herein. In making promotions, seniority and meritorious service in the department, as well as superior capacity, as shown by competitive examination, shall be taken into account. Individual acts of bravery may be treated as acts of meritorious service, and the relative weight therefor shall be fixed by the municipal civil service commission. No member of the police or fire departments shall hold any other office nor be employed in any other department of the city government.