Gravity is the driving force behing the flow of water in this example, and a static electromagnetic field (in a DC circuit at least) is the driving force behind the flow of electrons. The water can do work on physical object (waterwheels, etc), and the electrons can do work on electrical loads (lightbulbs, etc.).<p>However the static electromagnetic field in the DC circuit propagates through the material at near light-speed once the battery switch is thrown, which is a bit different. I suppose if you could throw a switch and turn gravity on or off it would be a closer analogy, i.e. the idea would be to fill the (sealed) maze with water in a zero-g environment (it would fill everywhere equally, comparable to the electons in the conductor with the power off), then turn on the gravity (or the pressure differential for the pipe version) and see what happened.