The steam is produced in the boiler A and reaches the cylinder B through the pipe C. The steam in the cylinder forces the piston D upwards, like in Papin’s invention, assisted by the counterweight K. At the piston D the force is coupled via the fixed rod E and in turn by a chain to the beam F. The counterweight K is attached via the chain H to the other side of the beam. The pump rod I is rigidly coupled to the base of the counterweight, being pushed up and down by the corresponding movements of the counterweight. By stopping the flow of steam through pipe C, by use of the stopcock, the contents of the cylinder are closed off. Water from the reservoir L is injected into the cylinder via the pipe P. (This point in the cycle is shown in the illustration). The injected water speeds up condensation of the steam in the cylinder, causing a vacuum. The piston is pushed downward by the air pressure from outside, moving the mechanically coupled beam F as well. This movement lifts the counterweight K and the coupled pump rod I upwards. The pipe R takes away the condensed water, S marks the section of the U-shaped pipe submerged in the reservoir, closing off the cylinder in a steam tight manner.