On Wed, 22 Jun 2005 19:10:18 -0500, "Hugo Schmeisser"
> wrote:
>
>This is all very interesting, to be sure. But nobody has answered my
>question of WHY?
>
>Was the positive-earth setup the result of a flawed understanding of
>electricity? Or was there some other reason to choose this layout?

Maybe not a "flawed understanding," but a change in theory
about electricity.
In school, studying automotive technology years ago, we were
told that the change from positive to negative grounding had to do
with electrical theory. I'm not enough of a physics major to make it
perfectly clear, but it had to do with whether current flows from
positive to negative, or from negative to positive. (And CURRENT flow
is not necessarily defined as ELECTRON flow).
Apparently there was a discovery or new understanding about
the basic nature of electricity, some time just before most auto
makers changed over from positive grounds to negative grounds. I
don't remember enough detail, but there was thought to be an advantage
to having it wired in a particular manner.
Most U.S. vehicles were changed in the middle 1950s. The
Brits came along about 5 years later.