"sm_jamieson" wrote in message
oups.com...
After recent trip to US/canada, I have observed that most toilets are
flushed by a type of syphon (or possibly active vaccuum judging by the
force of the suction) which completely empties the toilet bowl before
refilling it. There is a small hole pointing toward the back of the
outlet that refills the bowl. This is nothing like our washdown pans,
or even our vacuum assisted types, where the cistern water causes
partial vaccum in the outlet to assist emptying.
Anyone know more about these US toilets, design and evolution etc.
Of course the bowl syphon is not to be confused with the cistern syphon
(which seems to be dissappearing anyway).

I've no idea, but I'll never forget seeing a plumber on This Old House going
round a bog manufacturers. They had all the old standards of american bog
(something crazy like 7 gallon cistern) and a European style bog, and a
fluid dynamics lab etc. I'll never forget the plumbers face when he showed
him how the european bog flushed, he looked like he'd just been told we all
**** our pants instead of going to the lav...