It was called G-Line after its inventor, Dr. George Goubau. G-Line used a single insulated conductor with a cone shaped "launcher" at each end.
The first article states on page 124 that "when a wire is coated with dielectric material...the wire becomes nonradiating". Find a ham with a long wire antenna made from insulated wire and try to convince him of that!
It is also stated that "This new lead-in works on the surface wave transmission principle." It goes on to describe "the inner surface of the dielectric coating on the wire as one side of a capacitor and the outer surface as the other side". Is it possible to have a capacitor with only a dielectric and no plates?
On page 40, the 1956 article describes it as "a coaxial cable...except that the outer conductor is placed at infinity". It is beginning to sound to me like no one really understands how it works.
The 1:1 "balun" shown in Figure 2 of the 1954 article is certainly not a true 1:1 balun as described on page 189 of the ARRL's 1965 edition of "The Radio Amateur's V.H.F. Manual".
The 1954 article states on page 125 that "The balun has a flat standing wave ratio over the entire u.h.f. band." Yet "The Radio Amateur's V.H.F. Manual" states clearly on page 189 that a 1:1 balun is 1/4 wave. This means that it is very frequency dependent. Something just doesn't jibe.
Could it be that, unknown to the inventor, the "baluns" and launchers were converting the convential electrical current to a longitudinal (scalar) wave to travel through the single conductor and then back again at the other end?