Art Unwin wrote:
"It was Gauss who started a progression from statics*to
eletromagnetics by defining a clustered array as being in equilibrium
within a closed surface in his law of equilibrium.

Clustered array rings a bell! Is clustered array Art`s idea of a
Gaussian antenna?

J.D. Kraus wrote on page 185 of his 3rd edition of "Antennas" (a must
have):

"I delved into a monumental treatise on "Directional Antennas" by George
H. Brown of RCA. Buried deep in the article was, to me, an astonishing
calculation which indicated that parallel linear dipoles with spacings
of 0.125 wavelengths or less had higher gains than customary larger
spacings."

Terman in his 1955 opus gives the caveat, on page 906:

"A characteristic of all close-spaced arrays is that as the ratio of
size to antenna gain is reduced, the radiation resistance also goes
down---. The result is a practical limit to the amount of gain that can
be achieved in a compact antenna system, since as the resistance goes
down the fraction of the total power dissipated in the antenna loss goes
up. The Yagi antenna of Fig. 12-39, and the corner reflector, represent
about the best that can be achieved in a practical way with respect to
directive gain in a compact antenna array."

True today as it was more than 50 years ago.

Best regards, Richard Harrison, KB5WZI