JF Ptak Science Books Quick Post
This invention/innovation looks coy and sweet today, but it actually addressed an issue in 1917. This was the year that "Hollywood production" in movies really begins, though there was already an explosion of movie houses in the U.S., "Hollywood" or not. Cinemas were plentiful and packed, and from the numbers I've seen already in 1917 50% of Americans were going to the movies several times a month--this number would top out in the 30's when it approach nearly 70%. So ushers standing at points throughout a movie house finding stray seats for people being held back by the doorman could have signaled the number of available seats with his lighted fingers, and moved the waiting line along more quickly than a lot of whispered back-and-forth strolls around the house.
Popular Mechanics, April, 1917, p. 525,