On Tue, 28 Dec 2004 21:46:06 +0000, Ian Jackson
wrote:

Was it not an Ice Bucket which Faraday used to demonstrate the fact that
the electrostatic charges repelled each other as far as possible, and
therefore stayed on the outside of the bucket? The inside was
electrically dead.

Hi Ian,

Maybe it was part of an office party. Anyway, Gauss demonstrated that
electric charge FIELD LINES prefer as much separation as possible
(which conforms to your charges being repelled). With a curvature,
the field line normal to the surface will either cause line crowding
or line spreading depending upon the geometry. With a positive
curvature (the outside of a conducting shell) the lines spread; with a
negative curvature (the inside of a conducting shell) the lines
converge. Given that the bucket is conductive inside and out, he
demonstrated that line proximity within the bucket drove the charges
outside. This is not quite an issue of charges being repelled as far
as possible, or they would be uniformly distributed inside and out.

By the same logic (and experience), charge will accumulate on the
surface at the smallest radius - hence the points on lightning rods.
By extension, this is also the source of capacitor failure at either
the edges (smallest radius of a plate) or in surface burrs.

HCJB, in Quito, suffered from corona discharge and converted to loops
(misnomer, actually box), they still suffered when the corners
(smallest radius) supported the same discharge (being corner fed).
They shifted to a center feed point and put the hi voltage nodes at
the middle of a wire span.

73's
Richard Clark, KB7QHC