The vent flue of the projection room should be ample and lead direct to the open. It should be placed immediately above the machine, so as to carry off at once any fumes or smoke resulting from burning film. A flue above each machine would be preferable to a single flue over the entire group of machines. It is essential that the vent flue be composed of non-inflammable materials for its entire length, as it is liable to become intensely hot if there should be a serious fire. Perhaps the safest plan would be to construct a double flue with a generous air space between the inner and outer tubes.
In addition to the vent flues the projection room should have other ventilation. The operating room is often located directly under a roof of tin or of other material quickly heated by the sun, and with the heat from the machines, the temperature often becomes unbearable. Its ventilation, however, should not come from the auditorium, as that air is already vitiated and overheated.
An extra fireproof room, directly adjacent to the projection room, for rewinding film and for other necessary mechanical operations, should also be installed. The exit doors from the projection room should lead directly into and through this ante-room, and there should be exits from this outer room into a section outside of the auditorium.
Small chemical tanks should be attached to the ante-room side of the exit doors from the projection room, with exhaust nozzles penetrating into the interior of the latter room. This will enable the operator in an instant to turn on the cocks of these tanks and flood the projection room with a fire-extinguishing fluid in case of sudden fire.
As a matter of fact, the careful operator should never have a film fire. Such a contingency will not occur if his machine is kept in good working order - clean and well lubricated. In case of an accident, however, there should be buckets well filled with clean sand, and a wet blanket readily at hand to beat out the flame.
Main Floor Plan of Model Photoplayhouse (Egyptian).
Longitudinal Section of Model Photoplayhouse.