All aisles on the respective floors in the auditorium, having seats on both sides of the same, shall be not less than 30 inches wide where they begin and shall be increased in width toward the exits in the ratio of 1 inch to 5 running feet. Aisles having seats on one side only shall be not less than 2 feet wide at their beginning and shall increase in width, the same as aisles having seats on both sides.
All changes in the levels of the floors of such buildings, except under stairways, from story to story and except the necessary steps in galleries and balconies rising toward the exits, shall be made by inclines of no steeper gradient than two in ten within the auditorium, and rising toward the exits, and one in ten for all others.
Preceding each division of the theatre there shall be foyers, lobbies, corridors, or passages, the aggregate capacity of which on each floor or gallery shall be sufficient to contain the whole number to be accommodated on such floor or gallery in the ratio of 1 square foot of floor room for each person.
There shall be not less than two exit doors, each not less than 3 feet in width, located on opposite sides of the stage, and opening directly upon a street, alley, court, or courtway leading to a public thoroughfare.
All rooms in theatres for the use of persons employed therein shall have passages to at least 2 independent means of exit.
All doors of exit or entrance shall open outward, and shall be hung so as to swing in such a manner as not to become an obstruction in a passage or corridor, and no such doors shall be fastened so as to be inoperative when the building is occupied by an* audience.
No mirrors shall be so placed as to give the appearance of a doorway or exit, hallway, or corridor, nor shall there be any false doors or windows.
A common exit may serve for the main floor of the auditorium and the first gallery, provided that its capacity be equal to the aggregate capacity of the outlets from the main floor and the said gallery; and provided that the lowermost run of any exit leading from a gallery shall not open directly at right angles with the central axis of a common exit unless there is a clear space or landing of at least 1 1/4 times the width of the exit between the foot of such exit and such center line or nearest exit doorway.
Two distinct and separate exits shall be provided for each gallery and balcony above the main floor; and the same be located on opposite sides of the galleries.
All gallery or balcony exits shall start with a width of not less than 4 feet at the uppermost gallery.
Exits from balconies and galleries shall not communicate with the basement or cellar.
The aggregate width of all the exits previously described shall be estimated on a basis of not less than 20 inches for every 100 persons for whom seats are provided in the sections of the auditorium served by the respective exits.
In addition to the exits previously described there shall be one exit from each side of each gallery, balcony, and main floor of auditorium, at least 5 feet wide, leading to exterior balconies not less than 4 feet wide and 20 feet long on each side of the auditorium. From such balconies there shall be staircases extending to the ground level, which may be counterweighted, with risers of not over 8 1/2 inches and treads of not less than 9 1/2 inches, exclusive of nosing. The aggregate width of these emergency stairs shall be not less than 10 inches for every 100 people served thereby, no single stairs being less than 30 inches wide. If counterweighted, these stairs shall be lowered during all performances.
Where all such stairs are in an interior court, each run shall be covered by a light awning of iron.
Nothing herein shall prohibit the building of emergency stairs and exits inside the walls of the building, provided that they are surrounded by a fireproof partition not less than 4 inches thick separating the exits and stairways from the audience room or auditorium.
The commissioner shall have power to require a greater number or capacity of exits than is herein prescribed.
In every theatre there shall be over every exit, on the inside, and over every opening to a fire escape, on the inside, an illuminated sign, bearing the word "exit" or "fire escape," respectively, in letters not less than 4 inches high. The lights for the exit signs, passages, stairs, lobbies, auditoriums, rear of auditoriums, balconies, galleries, and for the balconies and stairs outside the building, shall be so arranged that they can be turned on or off independently of the means provided on the stage or in any part of the building in the rear of the proscenium wall. Every exit sign shall be kept illuminated, and every outside balcony and fire escape shall be kept well lighted during the performance, except outside exits during a performance before sunset.
Plans showing the exits and stairways shall be legibly printed so as to occupy a full page of every programme or play-bill.
In said buildings there shall be such number of gas pipe outlets as the commissioner may require, fitted with no less than two gas burners. Such burners shall be inspected and tried at least once in every three months by inspectors of the department, to ascertain if they are in proper working order. The inspector shall make a report of each visit, stating the condition of the burners and the action of the inspector in regard to them.
The commissioner shall have authority to order any defect in the working of such burners as are necessary for public safety to be remedied.
So much of this section as applies to the inspection of gas burners shall appy to buildings now used as theatres.