Enclosure openings

The number of openings in the front of the enclosure shall not exceed two projection openings, each not more than 36 square inches in area and one inspection opening not more than 36 square inches in area for each cinematograph apparatus or projector. All such opening shall be equipped with screens so operated that only one projection opening and one inspection opening can remain open at any one time and that all opening can be automatically closed from convenient positions both from inside and outside the enclosure.