Before Intel, Apple and Google, computing was a much more traditional affair. We're talking levers, gears, and other mechanisms that could all automate counting in some way or another. Russian scientist Vladimir Lukyanov, however, built one that ran on water.
Pruned has unearthed some lovely pictures and text about Lukyanov's computer, and it really is quite a sight to behold. Built-in 1936, it was the world's first computer for solving partial differential equations. A fundamental problem that anybody who did maths, physics, or engineering at college will testify is a pain in the ass to do by hand. Lukyanov fiddled around with a series of interconnected, water-filled glass tubes to solve the differential equations. The levels in certain tubes gave the answers while adjusting taps and plugs changed variables.
The device was actually used to solve problems related to cracks in concrete. Still, it inspired other devices and applications, which saw the same technology being used in fields such as geology, thermal physics, metallurgy, and rocket engineering. Not bad for some fancy plumbing.