Page:Collected Physical Papers.djvu/264

244 While the slider moved up to 0·30 volt, the immediate galvanometer reading was 171 divisions, and by the time the slider had commenced its backward movement to the left (producing a diminution of E. M. F.), the current value had risen from 171 to 197·5; the conductivity had gone on increasing, the resistance having fallen from 1,754 to 1,520 ohms.

I now give a table of results for electromotive variation of wider range from 0·1 to 0·6 volt.

Table V .—Showing the Current and Conductivity Variation of a Single-point Iron Receiver, due to Cyclic Electromotive Variation of Comparatively Large Range but Short of Critical Point

In the previous case it was shown that with a cyclic variation of the moderate range of 0·25 volt, the resistance was reduced to 8/10ths; in this case, at double the range, the reduction is very much greater, for the resistance falls to nearly 1/10th of its original value.

This confirms the conclusion previously made that the greater the range of electromotive variation the greater is the reduction of resistance.