readable

The Differential amplifier . At the top you have the input pipes, then the chambers, with output pulleys and drive racks. At the base of the cylinder you have a drain pipe. The differential amplifier is made up of a u bend filled with mercury. Works like a mercury barometer except instead of one side being open to atmospheric pressure, one end is connect to the high pressure, of the venturi pipe and the other to the low pressure side.
As the flow changes so does the differences between the two pressures. I.e as it goes up both do, by the same amount but the difference widens. Clever trick is to use the difference. As the difference changes so the mercury is pushed from one side of the U bend to the other. Small floats bob on the top of the mercury pools and these are mechanically linked to a wheel (pulley), which rotate depending on their level.

All very swimming I think you will find.