urinal

[RYeakle]

how does a urinal work

[hullaballo]

You pee in them

[New Forester]

RYeakle -- are you perhaps of the female persuasion? In which case you won't have seen one (if not, I don't understand what the question is...). Basically it's a trough on or next to a wall which drains into the sewer, via a u-bend like a basin's. As hullaballoo says, one pees in it if suitably equipped. If not kept very clean it smells pretty bad. Usually they have an automatic flush which washes them through with clean water every half an hour or so; I believe in America there's a manual flush. Er, that's it.

[tomd]

You can get female urinals too in places like Norway, don't ask me. In Leeds establishments another common part of the urinal is a pint glass filled with what looks like lager.

[New Forester]

Um... Strikes me that you may after all have been asking about the automatic flush, rather than the urinal? If so, there's an adjustable restrictor valve giving a trickle of water to fill a cistern, then some kind of mechanism in there which flushes it when it's full. Don't know how that works. I've also seen them operated by an electric timer. Apparently Virginia Woolf was caught short in a compartment in a non-corridor train, and peed out of the window through a rolled up magazine. Not sure whether there were other passengers present, or any line-side spectators...