§ 40-a. Examining boards of plumbers in cities. The existing boards for the examination of plumbers in cities of this state are continued and each shall be known as the examining board of plumbers. Such board in each city shall continue to consist of five persons to be appointed by the mayor, of whom two shall be employing or master plumbers of not less than ten years' experience in the business of plumbing, and one shall be a journeyman plumber of like experience, and the other members of such board shall be the chief inspector of plumbing and drainage of such city, or officer performing the duties of such inspector, and the chief engineer having charge of sewers in such city, but in the event of there being no such officers in such city, then any two other officers having charge or supervision of the plumbing, drainage or sewerage, whom the mayor shall designate or appoint, or two members of the board of health of such city having like duties or acting in like capacities.