The duty of extinguishing fires, preventing the spread of fires, preventing fires and protecting life and property from fire, within the city, and the power to do all things reasonably necessary for the performance of those duties, shall be and hereby are entrusted to the chief of the fire department. In addition, the chief shall perform those duties and exercise those powers otherwise provided in this code or assigned to him by the mayor and council. The chief shall have full control over the fire department and its members and equipment at all times, subject, however, to the approval of the mayor and city council. (1960 Code, Sec. 1-704)