2 rotary engines super simple

Ruth's Rotating engine.

"A revolving cylinder engine. Three cylinders, A,A,A radiate from a shaft set eccentric to an outer circle or ring on which the piston-connected sheaves revolve. The pistons take steam through the ports M,M,M, just past the shortest eccentric radius, and drives out the piston during a half revolution, when the exhaust is opened and the piston is pushed back by the eccentric ring." Hmmm. Not easy to see the point of this. If you wanted a compact and well-balanced steam engine, the Brotherhood three-cylinder radial would be a better bet. From "Mechanical Movements, Devices and Appliances" by Gardner D Hiscox, published by Sampson Low, Marston & Co in 1899.

The Almond Rotary engine. "Four single-acting cylinders set tangent to a shaft which is central to an outer shell. The pistons have jointed segmental plates at their outer ends which press against the outer shell and cause the cylinders and shaft to revolve by the eccentric direction of their pressure. Disc ports for steam and exhaust." Hmmm again. I am far from sure that pushing on a ring like this is an effective drive method. Even with rollers, I would have thought the pressure involved would have caused a lot of friction. From "Mechanical Movements, Devices and Appliances" by Gardner D Hiscox, published by Sampson Low, Marston & Co in 1899.

these engines are more than simples and they sure can be used today but we forgot then ...

it's a big looooooooose :(