netised needle
introduced into the small indicating helix (13.), and lastly the battery
contact broken, the needle was found magnetised to an equal degree
apparently as before; 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 current 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.

17. If the circuit between the helix or wire under induction and the
galvanometer 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 communications were first made, and then the wire under induction
connected with the indicating helix, no magnetising power was there
exhibited. But still retaining the latter communications, when those with
the battery were broken, a magnet was formed in the helix, but of the
second kind (14.), i.e. with poles indicating a current in the same
direction to that belonging to the battery current, or to that always
induced by that current at its cessation.

18. In the preceding experiments the wires were placed near to each other,
and the contact of the inducing one with the buttery made when the
inductive effect was required; but as the particular action might be
supposed to be exerted only at the moments of making and breaking contact,
the induction was produced 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 wire was stretched in precisely simil