There shall be provided, immediately under the glass of skylights, a wire netting, unless the glass contains a wire netting within itself. Over the stage there shall be metal skylights of an area or combined area of at least one-eighth of the area of said stage, fitted up with sliding sash and glazed with double thick sheet glass not exceeding one-eighth of an inch thick and each pane thereof measuring not less than three hundred square inches, and the whole of such skylight shall be so constructed as to open instantly on the cutting or burning of a hempen cord which shall be arranged to hold said skylights closed, or some other equally simple approved device for opening them may be provided.
53 P.S. § 24947