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absolute velocity, there is no inductive effect, because the two 
are relatively at rest. It follows therefore that in such a case 
the two are not charged up statically by the rotation in such a 
way as to tend to produce currents in opposite directions, but 
no effect at all is produced. 
V. In the apparatus for producing Electromagnetic Rotation, 
the effect depends merely on the relative motion of the magnet 
and the external portion of the circuit, and the case when the 
magnet rotates on its axis makes no exception to this law. 
When the magnet rotates on its axis, or when (conversely) the 
external portion of the circuit rotates about the magnet, the 
mode in which the effect is brought about is the same , and is 
dependent on relative motion. 
9. All the conclusions above summarized apply admittedly to 
the helix, and therefore to demonstrate them to apply to the 
magnet is only to reconcile completely two cases where the 
fundamental properties have been generally considered as iden- 
tical ; but which however could not be reconciled with each 
other, unless the above supposed distinction when a magnet 
rotates on its axis could be explained away. 
10. Of course on the adoption of Ampere’s theory of magnet- 
ism, all the conclusions above summarized necessarily apply to 
the magnet, since this theory was propounded on a recognition of 
the identity of the properties of the magnet and helix, founded 
upon observation. Faraday, who apparently considered that 
experiment compelled the adoption of the above exceptional 
hypothesis in the case where a magnet rotates on its axis, and 
which he himself designates as “ singular ” (opposing as it does 
the generalization of the properties of the magnet with those of 
the helix) — would no doubt have been ready to abandon the 
hypothesis, had he observed that such a course would be con- 
sistent with a just interpretation of the experimental results. 
