Some here may recall Ron Jarvis' wonderful models of significant early steam-engines of various types, parallel in individuality, technical significance, quality and medal-magnetism with Cherry Hill's models. They did know each other, via the major exhibitions.)
If so, you may remember his Newcomen Atmospheric Engine – a sizeable model approaching two feet high as I recall.
He made all its correct, scale, lead pipes, timber framing, "stone" blocks or bricks for walls (very probably cast and laid individually, not engraved slabs), wrought and cast "iron", square fasteners and the like; but realised he could not reasonably coal-fire the partly-spherical boiler, 2psi w.p. as original. It is about the size of an orange – and dimpled like one to represent the hand-forged iron plates, though actually of copper or brass.
So Ron, a retired Civil-Service Scientist who taught himself computing when using computers meant knowing computers not just using them, decided on something that could not have come to Newcomen… electricity.
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Therefore the boiler contains a small, low-voltage electric element, controlled by a temperature probe and an integrated circuit discreetly concealed in the machine's base. The on-off switch and I think a small temperature or pressure meter (electric), are set into a panel in one side of the plinth.
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I do hope this and his other works have found a proper home where they can be appreciated; but I remember Ron would joke about this being the only example of an Eighteenth-Century Atmospheric-Engine with Computer-Control!