XVIII
ON THE DIMENSIONS OF MAGNETIC POLE IN
DIFFERENT SYSTEMS OF UNITS
(Wiedemann's Annalen, 24, pp. 114-118, 1885.)
Two years ago this subject was discussed in the Annalen,' and
even more vigorously in the Philosophical Magazine. In
general we may now regard the matter as settled; but I think
there is still one point which admits of a more complete ex-
planation, and as the question is one of principle it is worthy
of attention. Between the electromagnetic² and electrostatic
systems of units there appeared to be a certain discrepancy.
In the former there was agreement as to the starting-point,
viz. the magnetic pole, and also as to the electrical pole whose
dimensions were deduced; whereas in the latter a difference of
opinion was possible, not indeed as to the starting-point, viz.
the electrical pole, but as to the magnetic pole deduced from
it. Side by side with Maxwell's electrostatic system there
appeared that of Clausius. Now even if it is shown that
neither of these is necessarily incorrect-that the only question
is, which of the two is preferable—there may yet remain in
the minds of many physicists a feeling that both of them, and
therefore the electrostatic system generally, are inferior to the
magnetic system, respecting which no doubt has been raised;
1 Cf. Clausius, Wied. Ann. 16, p. 529, 1882, and 17, p. 713, 1882; v.
Helmholtz, Wied. Ann. 17, p. 42; also a series of papers in the Phil. Mag.
(Ser. 5) 13, and 14, 1882. [Phil. Mag. 13, pp. 376, 427, 429, 431, 530; 14, 124,
225, 357.
Translations of Clausius' two papers will be found in the same
journal, 13, pp. 381-398, and 15, pp. 79-83; and of Helmholtz's paper in 14, pp.
430-440.-TR.]
2 Called by Clausius electrodynamic. [In this volume, as in the Electric
Waves, "elektrodynamisch" is generally rendered as "electromagnetic.”—TR.]