35 



NINETEENTH CENTURY. 



PT. or. 



and the magnet was fixed. He now sent a current through 

 the wires <?, e' } and immediately in the cup A the magnet d 

 began to move round the fixed wire/ while in B the wire/' 

 moved round the fixed magnet, d'. In this way he proved 

 that magnetic and electric currents move round and round in 

 circles at rigJit angles to each other. He made the magnet go 



Faraday's Experiments on the Rotation of a Magnet and of an Electric Wire 



(Brande). 



A B, Section of cups of mercury, c, Copper rod. The current coming in at e passes 

 up through the mercury in A, and along the rod c down into the mercury in B, 

 and back by e! to the battery. On its way it causes the floating magnet, d, to 

 revolve round the rod, f, and the loose wire, J 1 , to revolve round the fixed 

 magnet, cf. 



a great way round the circle, but not spin quite round as 

 the wire had done. Ampere, however, who repeated the 

 experiment, succeeded in making the magnet spin round and 

 round like the hands of a clock. 



Electric Current produced by means of a Magnet. 

 Faraday's mind was now full of the wonderful effect which 

 electricity and magnetism produce on each other, and he 

 began to consider whether it might not be possible to reverse 

 Ampere's second experiment (p. 347), and instead of making 

 a magnet by means of an electric current, whether he might 

 not set up an electric current by means of a magnet. 



