Galleries must also be provided with at least one line of fire escapes, leading to an open court, fireproof passage or street without re-entering the same or any other building. If the fire escape leads to a point in the court nearer the street than any exit, there must be a width of not less than 4 feet in the clear between the outer edge of the fire escape and the outer wall of the court. All fire escapes must have balconies, not less than 3 feet 4 inches in width in the clear, and not less than 4 feet 6 inches long, and from said balconies there shall be staircases extending to the ground level, with a rise of not over 7 3/4 inches and a step of not less than 9 1/2 inches, and the width of the stairs must not be less than 3 feet 4 inches.
Apparatus for projecting motion pictures shall be contained in a fireproof booth or in-closure constructed as required by law. The booth in which the picture machine is operated shall be provided with an opening in its roof, or in the upper part of its side walls leading to the outdoor air, and with a vent flue, which shall have a minimum cross-sectional area of 50 square inches and shall be fireproof. When the booth is in use, there shall be a constant current of air passing outward through said opening or vent flue, at the rate of not less than 30 cubic feet per minute. The requirements of this section shall apply to portable booths and booths in open-air theatres, as well as to motion picture theatres.
All the provisions of this article shall apply to existing places of entertainment where motion pictures are exhibited under common show licenses, in case the seating capacity be increased; and, in case the seating capacity be not increased, all the provisions of this article shall apply, except the provisions of paragraphs 500, 501; subdivisions 1, 3 and 5 of paragraph 502 and subdivisions 3, 4 and 5 of paragraph 503, but the commissioner of licenses shall have power in his discretion to enforce the provisions of subdivisions 3 and 4 of paragraph 503, relating to exits and courts.
An existing place of, entertainment seating 300 persons or less, where motion pictures are exhibited in conjunction with any other form of entertainment, must comply, before a reissuance of its license, with the provisions of article 25 of this chapter, relating to theatres seating more than 300 persons. But, if such existing place of entertainment shall discontinue all other form of entertainment except the exhibition of motion pictures, it may be licensed in accordance with the provisions of first paragraph of this section.
The seating capacity of each open-air motion picture theatre, as defined in paragraph 30 of chapter 3 of this ordinance, shall be such as shall be prescribed by the commissioner of licenses. All such theatres shall conform to the fol-lowing requirements:
The number and width of all aisles shall be as prescribed by the commissioner of licenses, but no aisle shall be less than 4 feet wide;
At least 2 separate exits, remote from each other, shall be provided, and no exit shall be less than 5 feet in width; for every 25 persons to be accommodated in excess of 300, the total width of exits shall be increased 1 foot. All exits must be indicated by signs and red lights, and doors must open outwardly;
Seats must be stationary, with backs 32 inches apart, and so arranged that no seat shall have more than 7 seats intervening between it and an aisle. Chairs must be either securely fastened to a wood or concrete floor, or all chairs in a row must be fastened together, and at least 4 rows must be securely fastened to 1 frame; except that, where refreshments are served, tables and unattached chairs or benches used with them may be permitted;
The floor must be constructed either of wood, with sleepers, or concrete; it must extend at least 5 feet from the seats on all sides; provided, however, that, in the discretion of the commissioner of licenses, a gravel floor may be substituted for wood or concrete.
In addition to the foregoing requirements, the provisions of subdivisions 2 and 4 of paragraph 502 and paragraph 504 of this article shall apply to all open-air motion picture theatres.