Earlier quoted context omitted.
This is probably old news to people interested in nonstandard methods of computation, but it just occurred to me that the fluid-based analogy to transistors is straightforward to construct: S | | -------| | G \/\/|##| | -------| | | | D This is essentially a pressure regulator, except that the pressure is controlled by an independent signal. Pressure in G pushes a spring-loaded piston to block flow from S to D (a sli…
Related: https://en.wikipedia.org/wiki/Phillips_Machine "The Phillips Machine is an analogue computer which uses fluidic logic to model the workings of an economy."
See also the Glooper in Pratchett's Making Money.