Just daft curiosity... can't seem to find any resource on the web or
newsgroups that describes the periodic flushing mechanism (there's
plenty of info out there regarding w.c's), and being considerably
shorter than 7ft 6ins I can't see inside.

Presumably there's a siphon at work, but how is it suddenly triggered
by a very slow trickle of water at the inlet? I always thought you
needed a reasonable rush of water to get a siphon started.

Incidentally, I know you can get all manner of electronically
triggered cisterns - I'm just referring to the mechanical kind.

It's sad, but please put me out of my misery.

Thanks,
Tim.