§ 211. Sealer of weights and measures. The sealer of weights and measures shall, within the city, have the powers and perform the duties of sealers of weights and measures of towns under the general laws of the state. He shall supervise the weighing of coal and perform such other duties as may be prescribed by law or ordinance of the common council. He shall receive a salary, to be fixed by the board of estimate and apportionment, and no fees shall be charged or collected by him or by the city for his services.