Re: OT: Possible French idiom?

Some people said, so I replied:

> Another question: Why in English do we say 'Slow down!' and 'Hurry up!'?
Why not 'Slow up!' and
> 'Hurry down!'? Or is this just how idioms work - they make no sense - or
is there some
> (historical?) reason for using 'up' with one verb and 'down' with another?
From my experience, both "slow down" and "slow up" are perfectly acceptable,
and I've both heard and used both. As for any difference or origin, I can't
think of much. My best guess is that if you have a spinner a la Wheel of
Fortune (where it has a bunch of poles that click something), as the wheel
slows down in a rotation, the sound produced "goes down" in pitch (tone? I
don't know sound terms).

-Keith