On Sun, 14 Oct 2007 01:31:49 +0000, Larry wrote:

Your "tarnished" silver-plated ground strap is fine....mine, too.

It is well known that copper is somewhat soluble in sea water. After
all it was used to cover ships bottoms to retard marine growth. Had to
be in solution to be toxic. Silver is not very subject to attack. They
use it for medical work: I have silver wire in my jaw.
So, silver may well outlast copper in the ground. Life of either
should be long enough, in any case. They often ground electrical
transformers with a six foot or so copper rod driven into the ground
at the base of the pole. Fairly heavy conducters running down the
poles. I wonder if people steal them. They do get killed trying to
steal energized wire. You are supposed to ground your end of the
neutral, but whatever.

Casady