Posted by Tom Napier on August 09, 2013 at 11:36:55 user Didymus.
In Reply to: Re: Plumbing posted by John Nichols on August 09, 2013 at 07:16:13:
I recently bought an original (1939?) copy of How it works and how it's done. by Ellison Hawkes. It was one of my favorite books (along with AR's of course) when I was a child in the 1950s but that copy is long gone.
To quote (p169), "The hydraulic ram, an old but remarkably efficient form of pumping machine, consists of a casting to which three pipes and an air vessel are attached."
A detailed description follows, along with a cross-sectional diagram. The text indicates that a head of as little as two or three feet of water was sufficient to drive it but doesn't mention a typical delivery height. The closing of the escape valve forces the resulting pulse of high pressure water through the delivery valve. The delivery valve then closes and the escape valve reopens, allowing low-pressure water to flow to waste until the escape valve closes, restarting the cycle. The air reservoir smooths the pulses into a steady high pressure supply, presumably to a cistern in the attic.
I suspect they were rather noisy devices as they were deliberately inducing the "hammering" that occurs when air gets into a plumbing system.