In another post, those of us from THIS side of the pond were
shown the Texas Bugcatcher antenna (easily googled), and its
extensive website.

It would seem to be a universal panacea for those with small
gardens, subject to the availability of a ground plane.

It discusses capacity hats. And my question is this, why is it called
a capacity hat, because calculation of the capacity between the hat
and the ground will only give, at a guess, a miniscule fraction of a puff.

My reasoning is that because the waves spread out in all directions
in the hat, then there is no, or very little, radiation from the hat because
of field cancellation, but when the waves all return simultaneously to the
main element, they have incurred a phase change that you'd get had there
been a capacitor in circuit?

(Always willing to learn more, and to be corrected if my thought
experiment has gone up a blind alley, or in this case, a capacity hat
alley!)