(a) All stairways and corridors in every building or structure in which theatricals, shows and amusements are offered, operated, presented or exhibited for gain shall be supplied with a supplemental lighting system of electricity or gas, and such system shall be independent of all other lights in such building or structure and shall be in operation during the entire period that such building or structure is open to the public and until the entire audience has left the building.
(b) The word "Exit" shall appear in letters at least six inches high over the opening of every means of egress from such building or structure, and a red light shall be kept burning over such sign at all times at which the building is open to the public.
(1929 Code, § 344)