Mark Kinsler wrote:

> "The economic critic Stuart Chase told the Women's City Club of New
> York that the advent of "talkies" had thrown ten thousand movie house
> technicians out of work."

Mark wondered what aspect besides organ maintenance of silent movies
required all those technicians.

It is true that the advent of sound pictures threw projectionists out
of work, although that number may be suspect.  What happened is this:

Prior to sound films, projectors were generally hand-cranked.  This
required two or three projectionists at a time, the third man being a
"rewind boy", usually an apprentice learning the trade.  Hand-cranking
was required by the fire laws in many cities, to keep a projectionist
in close attendance to the projector since it ran nitrate-based film
which was flammable to the point of being nearly explosive, illuminated
by the open flame of an arc lamp.  In those days theatre fires, with
great loss of life, were not uncommon.

However, another reason for hand-cranking was to give the organist,
Photoplayer operator, or orchestra conductor the ability to vary the
speed of the film to synchronize with the music.  An indicator by each
machine, controlled by the musician, told the projectionist to "crank
slower" or "crank faster".  With the advent of sound, the requirement
of a steady, uniform film speed necessitated motor-driven projectors.
Elaborate fire-prevention and isolation equipment was built into the
booths and projectors, and the demise of the two- and three-man
projection booth followed quickly.

Dick Twichell