§ 49. Duties of inspectors; reports. The inspector or inspectors of plumbing appointed under the provisions of the preceding sections of this article, in addition to the duties prescribed by law or ordinance and those which may be enjoined or required by the appointing power of the city in which they shall be appointed, shall be to inspect the construction and alteration of all plumbing work performed in such city, and to report in writing the results of such inspection to such appointing power of their respective cities. They shall also report in like manner any person engaged in or carrying on the business of employing plumber, without having the certificate hereinbefore provided.