Abstract: The engine has at least first and second stepped cylinders with the pistons therein operated from the same crankshaft at different portions of the engine cycle. The pistons in the cylinders to define a combustion space and first and second air compression spaces. The combustion space can expand a combusted fuel/air mixture and a double-acting air cylinder of the first cylinder is connected to deliver charging air to its own combustion space and deliver purging air to the combustion space of the other cylinder. Pressure lubrication for the cylinder walls is provided by oil sprays through openings in the piston skirts, with drainage back to the crankcase.

Abstract: A thumb pick for stringed musical instruments comprised of a flat triangular shaped main body. A short hook projects outwardly at right angles from the lower portion of said main body. One end of a flexible band is anchored to a hole near the top of said main body; the other end of said flexible band is anchored to said hook and stretches over the thumb nail holding the pick in place with a positive non-slip grip.