There is some evidence that the ancient Romans used non-trivial (at least by ancient standards) fluidic logic in some of their waterworks. If you have a stream of water coming down a hill and it meets a narrow Y, it doesn't take much effort (water and/or mechanical) to change the course from one to the other exit, so you can have *amplification*. I've always been fascinated by ancient Roman engineering, because some of these systems operated more-or-less continuously for hundreds of years. I don't know very many modern systems that can operate for more than a few years without substantial maintenance and repair. For example, I've climbed through the water channel at the top of the Pont du Gard, and the channel is about the same size as a man (ok, a short, ancient Roman-sized man), so that a man could walk through the channel even with the stone roof in place. However, this would have been impossible without first turning off the water, so there had to be a complex series of gates/diverters to enable service persons to remove debris from the channels. I noticed that every once in a while, the water channel would drop vertically and change direction; I believe this enabled any large debris in the channel to be sorted out from the water. I have also speculated that the ancient Romans utilized some of the aqueducts to transport wood from high up in the mountains in a manner similar to the way lumber was transported from the California mountains into Sacramento; the ancient Roman ovens used for baking their bread consumed prodigious amounts of wood for fuel, and post Augustus (?), delivery trucks/carts were only allowed to use the streets in the middle of the night (NYC, are you listening?). At 11:27 AM 3/22/2017, rcs@xmission.com wrote:

This had no moving parts, except for the water. There must also have been a pump somewhere.

Imagine a sloped surface, with various bumps & channels. Water is supplied at the top, and runs down the surface, being deflected by the topography. The logic comes from non-linear behavior of streams & droplets. And maybe some 'sticky' effects, like a stream that sticks to the left side of a channel for historical reasons, but can be switched to the right side, or perhaps the center. This would seem to lead to a fixed pattern, or a simple repetition; to get interesting behavior, some feedback would be necessary. I don't know the mechanism.

Rich -------- Quoting Henry Baker <hbaker1@pipeline.com>:

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Ummm, ancient Greek water clocks?

At 12:08 AM 3/22/2017, rcs@xmission.com wrote:

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IIRC, someone has done a water fountain with fluid logic, making some sort of counter -- maybe a LFSR shift register. Has anyone seen this?

Rich