The error in your logic may be in applying what would happen if a crowd of
people suddenly had to go through a narrowing of the path. That would indeed
effect everything past the narrowing. The water is powered by the pressure
pushing it through and this will make the water go faster in the narrow
section so largely negating the sort of effect one would expect by using the
people analogy.

With water the flow is effected by not just the bore of the pipe but by the
length of pipe so a very short narrow section will not effect it as much as
one would think.

JohnB



"sw" wrote in message
...
Rod wrote:

I thought I might be mistaken, which is why I asked :-) But it does seem
logical that one really narrow bit will determine the flow rate
everywhere beyond that point. Something to reason through as I do the
shopping...

thanks
sarah

--
Waist deep, neck deep
We'll be drowning before too long
We're neck deep in the Big Muddy
And the damned fools keep yelling to push on