High pressure engine proposed by Jacob Leupold

Drawing of High Pressure Engine proposed by Jacob Leupold, 1724, prepared in the Museum, 1897.

Jacob Leupold, in 1724, published a sketch and description of a proposed high-pressure engine for working a force pump. There were to be two vertical single-acting steam cylinders, two pumps and two rocking beams; but the steam and exhaust for both cylinders were to be controlled by a single four-way cock, so that the cylinders worked alternately. The weight of each steam piston was to exceed that of the pump plunger at the other end of its beam so that the in-strokes would be done by gravity, while the exhaust steam passed into the atmosphere. The use of a non-condensing engine and of a four-way cock, which Leupold pointed out could be worked automatically, are the leading features in this proposal.