82 Faraday on Neio Elect ro-Magnetkal Motions, 



nexion with both wires be inverted, or if the pole be changed, 

 the hne it describes is in the opposite direction. If these 

 two opposite currents be made by bending a piece of silked 

 wire parallel to itself, fig. 9, it, when connected with the 

 apparatus, becomes a curious magnet ; with the north pole, for 

 instance, it attracts powerfully on one side at the line between 

 the two currents, but repels strongly to the right or left ; whilst 

 on the other side the line repels the north pole, but attracts it 

 strongly to the right or left. With the south pole the attrac- 

 tions and repulsions are reversed. 



When both poles of the needle were allowed to come into 

 action on the wire or wires, the effects were in accordance with 

 those described. When a magnetic needle was floated on 

 water, and the perpendicular wire brought towards it, the 

 needle turned round more or less, until it took a direction per- 

 pendicular to, and across the wire, the poles being in such 

 positions that either of them alone would revolve round the 

 wire in a circle proceeding by the side to which it had gone, 

 according to the law before stated. The needle then approaches 

 to the wire, its centre (not either pole) going in a direct line 

 towards it. If the wire be then lifted up and put down on the 

 other side the needle, the needle passes on in the same line 

 receding from the wire, so that the wire seems here to be 

 both attractive and repulsive of the needle. This effect will be 

 readily understood from fig. 10, where the poles and direction 

 of the wire is not marked, because they are the same as before. 

 If either be reversed, the others reverse themselves. The 

 experiment is analogous to tlie one described above ; there the 

 pole passed between two dissimilar wires, here the wire between 

 two dissimilar poles. 



If two dissimilar wires be used, and the magnet have both 

 poles active, it is repelled, turned round, or is attracted in 

 various ways, until it settles across between the two wires ; 

 all its motions being easily reducible to those impressed 

 on the poles by the wires, both wires and both poles being 

 active in giving that position. Then if it happens not to be 



