On Mon, 25 Aug 2014 23:53:10 EDT, just as I was about to take a herb,
"gareth" disturbed my reverie and wrote:

The wire must be insulated from earth, because the reason is to provide
the counterpoise that the otherwise lossy earth provides.

Ideally, there should be a complete earth mat of several radials, but
as you intend the use of a longwire, then running along the ground
underneath the long wire should suffice.

Thanks Gareth. Will be done.
--
73's de Guy G4DWV/4X1LT