A screw with no water to lift and no job. Eleven marbles, one motor. A marble in the screw sits still at the bottom of its turning cage: the screw only turns, the turn of the thread under the marble moves up, and the marble goes up with it without ever rolling uphill. At the top it drops onto three tuned brass bars, rolls home along the floor, and the screw takes it again. The goat on top watches the red one.

Every knock and every music-box note is timed by the machine itself.

Stay for the end.

Which machine with no job should we build next?