Section 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.