Law of the Induction of an Electric Current upon itself. 29 
If a current be generated in a conducting wire whose cross sec- 
tion is an ellipse, in such manner that the rate of development 
through any fibre, shall be in the inverse ratio of the chord bi- 
sected by that fibre, and in the direct ratio of the diameter to 
which that chord is parallel, the inductive force will be the same 
in all parts of the cross section. 
16. These results, if the fundamental law of induction as laid 
down be really true, leave no doubt that the initial development 
of acurrent in an extended wire, is more rapid at and near the 
surface of the wire than at the centre, and that in round wire it 
follows the law indicated in 13. In the case of a galvanic cur- 
rent, the resistance to conduction would come in as an element 
and interfere with this law as the quantity of current increases, 
until finally the electro-motive force comes into equilibrium with 
the resistance to conduction, when the current becomes uniform 
in quantity throughout the mass of the wire. But in discharges 
-0l common electricity, and in the slight currents that take place 
in electric waves of moderate length, there is strong reason to 
believe that the resistance to conduction is in most cases trifling 
of this question of the time required for the current 
maximum, or of the rate at which it will approach it 
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