128 MR. FARADAY’S EXPERIMENTAL RESEARCHES IN ELECTRICITY. 
14. When the battery contact was first made, then an unmagnetised needle 
introduced into the small indicating helix, and lastly the battery contact 
broken, the needle was found magnetised to an equal degree apparently with 
the first ; but the poles were of the contrary kind. 
15. The same effects took place on using the large compound helices first 
described (6. 8.). 
16. When the unmagnetised needle was put into the indicating helix, before 
contact of the inducing wire with the battery, and remained there until the 
contact was broken, it exhibited little or no magnetism ; the first effect having 
been nearly neutralised by the second (13. 14.). The force of the induced cur- 
rent upon making contact was found always to exceed that of the induced 
current at breaking of contact ; and if therefore the contact was made and 
broken many times in succession, whilst the needle remained in the indicating 
helix, it at last came out not unmagnetised, but a needle magnetised as if the 
induced current upon making contact had acted alone on it. This effect may 
be due to the accumulation (as it is called) at the poles of the unconnected 
pile, rendering the current upon first making contact more powerful than what 
it is afterwards, at the moment of breaking contact. 
1 7- If the circuit between the helix or wire under induction and the galva- 
nometer or indicating spiral was not rendered complete before the connexion 
between the battery and the inducing wire was completed or broken, then no 
effects were perceived at the galvanometer. Thus, if the battery communi- 
cations were first made, and then the wire under induction connected with the 
indicating helix, no magnetising power was there exhibited. But still retain- 
ing the latter communications, when those with the battery were broken, a 
magnet was formed in the helix, but of the second kind, i. e. with poles indi- 
cating a current in the same direction to that belonging to the battery current, 
or to that always induced by that current in the first instance. 
1 8. In the preceding experiments the wires were placed near to each other, 
and the contact of the inducing one with the battery made when the inductive 
effect was required ; but as some particular action might be supposed to be 
exerted at the moments of making and breaking contact, the induction was pro- 
duced in another way. Several feet of copper wire were stretched in wide zigzag 
forms, representing the letter W, on one surface of a broad board ; a second 
