Hit and miss engine

Okay I’ll bite: what is/was this cool looking motor used for?

@watersprite That is called a stationary engine.
They are standing water cooled in the upper rectangular casting that surrounded the cylinder and ran on just about any liquid fuel that could ignite.
The spark was provided by a magneto, so they required no electricity added to them to run.
They were used for portable power plants around agriculture and in industrial settings, powering anything that needed rotational force, such as a pump.
As big as it is, this one is only a 5 horsepower unit.
The hit and miss part of it was how the speed was governed where the power strokes are only allowed to maintain a steady speed under varying loads.
This was accomplished by altering the valve timing on them.