require the skill and experience of a civil engineer. He shall ascertain, record and establish monuments of the city surv ey and from thence extend the surveys of the city, and locate, establish, and survey all city property, and also private property abutting on the same, whenever directed by the mayor; shall prepare and submit plans, maps, specifications, and estimates for buildings, streets, bridges, docks, and other public works, and supervise the construction and repair of the same; shall make such tests and inspection of engineering materials used in construction and repair as may be necessary to protect the city from the use of materials of a poor or dangerous quality; shall inspect and report upon the condition of public property and public works whenever required by the mayor; shall have the care and custody of all public buildings, when erected, including markets and slaughterhouses and all buildings rented for city purposes, and of any system now or hereafter established for lighting the streets, public places, and public buildings of the city; shall prevent the encroachment of private buildings and fences on the stre ets and public places of the city; shall inspect and supervise the construction, repair, removal, and safety of private buildings, and regulate and enforce the numbering of houses, in accordance with the ordinances of the city; shall have the care of all public streets, parks, and bridges; shall maintain, clean, sprinkle, and regulate the use of the same for all purposes as provided by ordinance; shall collect and dispose of all garbage, refuse, the contents of closets, vaults, and cesspools, and all other offensive and dangerous substances within the city; shall have the care and custody of all public docks, wharves, piers, levees, and landing places, when erected; shall have general supervision and inspection of all private docks, wharves, piers, levees, a nd landing places, and other property bordering on the harbor, river, esteros, and waterways of the city, and shall issue permits for the construction, repair, and removal of the same, and enforce all ordinances relating to the same; shall have the care an d custody of the public system of waterworks and sewers, and all sources of water supply, and shall control, maintain, and regulate the use of the same, in accordance with the ordinances relating thereto; shall inspect and regulate, subject to the approval of the mayor, the use of all private systems for supplying water to the city and its inhabitants, and all private sewers and their connections with the public sewer system. He shall file and preserve all maps, plans, notes, surveys, and other papers and d ocuments pertaining to his office. He shall supervise the laying of mains and connections for the purpose of supplying gas to the inhabitants of the city. He shall have power subject to the approval of the mayor, to cause buildings dangerous to the public to be made secure or torn down, and shall supervise and regulate the location and use of engines, boilers, forges, and other manufacturing and heating appliances in accordance with law and ordinance relating thereto. He is authorized to charge, at rates to be  fixed by the Board with the approval of the Governor-General, for sanitation and transportation services and supplies furnished by his department. 

