370 MR BALFOUR STEWART ON EARTH- CURRENTS, ETC. 



od. The values of the earth-currents collected during periods of magnetic dis- 

 turbance are chiefly remarkable for their great range, with frequent change of 

 sign. This also admits of a simple explanation on the induction hypothesis. 



Atk, This hypothesis would therefore appear to be sufficient to account for all 

 the earth-currents hitherto observed. 



