 DATE: During the scene in the theater screening  _Man Who Laughs, The (1928)_ (qv), we see the beam from the  projection room. It is shining out of a single window. In the 40s,  theaters used two projectors and changed reels (alternating  projectors) every 20 minutes or so, unlike modern theaters that use  only one projector per screen. The back wall should have shown two  projector ports, two viewing ports for the projectionist and a large  port for the spotlight.