  The beam-normal single-spin asymmetry, $B_n$, exists in the scattering of
high energy electrons, polarized transverse to their direction of motion, from
nuclear targets. To first order, this asymmetry is caused by the interference
of the one-photon exchange amplitude with the imaginary part of the two-photon
exchange amplitude. Measurements of $B_n$, for the production of a
$\Delta(1232)$ resonance from a proton target, will soon become available from
the Qweak experiment at Jefferson Lab and the A4 experiment at Mainz. The
imaginary part of two-photon exchange allows only intermediate states that are
on-shell, including the $\Delta$ itself. Therefore such data is sensitive to
$\gamma\Delta\Delta$, the elastic form-factors of the $\Delta$. This article
will introduce the form-factors of the $\Delta$, discuss what might be learned
about the elastic form-factors from these new data, describe ongoing efforts in
calculation and measurement, and outline the possibility of future
measurements.
