When researching historical magic I came across some of the theatrical features of ancient temples like “Heron’s Temple Doors” which open as if by magic when the priests would lite a fire on the alter. One might think this was done simply with hidden slaves or something of that nature, but in fact it is done by the first real application of hydraulics and pneumatics.
There are many examples of these types of devices in the ancient world.
It occurred to me it might be fun to research and maybe create a model or two of some of these devices.
Hence, another page of notes.