Comments by "John D" (@johnd8892) on "Branch Education" channel.

They were open and closed manually at first. However one young machine attendant found that this was very boring work and was inspired to invent and set up an arrangement for this to be done automatically. Very slow moving engines so manual operation not too taxing. Unfortunately his name not recorded and not whether he he was rewarded and promoted for his intelligence or just did himself out of a job. So the story goes.
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Other sources say the Hero of Alexandria steam turbine was put to work to open a set of temple doors with any apparent human assistance and so adding enormously to the mystical nature of that temple. But keeping it mystical meant keeping it secret to the world at large. So not just a toy could have been the germ of huge progress if the principles were more widely understood.
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