In 1887, Ion I. Tabarici patented a tailless monoplane with three propellers, one puller and two pushers.

-The engine is two-cylinder but with a piston in the middle, with two active faces.

-The device was not released until 1914. We see that the engine is horizontal and the central rod is the one with the connecting rods at each end.

-Inside the cylinders it is difficult to know how the engine works. It is clear that the U-shaped tube moves with the central rod.

“Top view of the engine assembly”