Newbie that don't understand

[Steve Holden]

"Jonathan Hogg" <jonathan at onegoodidea.com> wrote ...
> On 30/6/2002 1:55,  "Jim" <jbublitzNO at SPAMnwinternet.com> wrote:
>
> > Some British
> > sports cars from the 50's and 60's have the positive
> > terminal connected to the chassis (ground for a car),
> > so they have a -12v (-6v?) electrical system (or "positive
> > ground"). There is no difference, however, between the
> > battery in an American car and these British cars - just
> > a difference in reference point. As Einstein said, it's
> > all relative..
>
> [Still being off-topic:]
>
> Wouldn't a positive ground car rust faster? I seem to vaguely remember
> something from school physics about negative ground helping to slow
> oxidation by replacing electrons in the chassis.
>
> If I remember rightly, that's also why iron ships have (or used to have?)
> zinc plates bolted to the hull on the inside. When the zinc oxidises it
> gains a negative charge which replaces electrons being stripped from the
> iron on the outside.
>
Weren't these devices called "sacrificial anodes", or is my (also ageing)
memory deceiving me?

regards
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Steve Holden                                 http://www.holdenweb.com/
Python Web Programming                http://pydish.holdenweb.com/pwp/
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