  Using the canonical formalism, Compagno and Persico [J. Phys. A: Math. Gen.
35 (2002) 3629--45] have calculated the 'radiation-reaction' force on a uniform
spherical charge moving rigidly, slowly and slightly from its position at the
time when the transverse electric field is assumed to vanish. This force is
shown to result in the same time-averaged self-force as that which has been
obtained by different means for the test charge of a Bohr--Rosenfeld
field-measurement procedure and which Compagno and Persico claimed to be
incorrect.
