There shall be elected by the qualified voters of said village, annually, on the first Tuesday of April, a president and five councilmen, an assessor, collector, street commissioner, marshal and police constable, and quadrennially a police magistrate, who shall hold their respective offices until their successors are elected and qualified; provided when the inhabitants of said village number three thousand an additional police magistrate and constable may be elected. All vacancies, except of police magistrate, shall be filled by appointment, to be nominated by the president and confirmed by the council. Removal from the corporate limits, refusal to serve or neglect to serve for one month, shall constitute a vacancy.