582 



3rd. That there is no apparent difference, except in degree, be- 

 tween the currents collected in times of great magnetic disturbance 

 and those collected during the ordinary calm periods. 



4th. That the prevailing directions of earth-currents, or the cur- 

 rents of most frequent occurrence, are approximately N.E. andS.W. 

 respectively. 



5th. That there is no marked difference in frequency, duration, or 

 value, between the N.E. and the S.W. currents. 



6th. That (at least during calm periods) there are definite cur- 

 rents of less frequency from some place in the S.E. and N.W. qua- 

 drants respectively. 



7th. That the direction of a current in one part of a plane on the 

 earth's surface (at least as far as the S.E. district of England is 

 concerned) coincides with the direction in another part of the plane ; 

 and if the direction changes in one part, it changes in all parts 

 of the plane. 



8th. That the relation in value between currents in a given part 

 of the plane and currents in another given part is not constant, but 

 is influenced by local meteorological conditions, and varies from time 

 to time. 



9th. That the value of the current of a given length, moving in a 

 given line of direction, is not necessarily the same as of a current of the 

 same length on the same line of direction produced, and that their 

 relative value depends on the physical character of the earth inter- 

 posed between the respective points of observation, and is tolerably 

 constant. 



10th. That the currents which have formed the basis of these 

 investigations are derived currents from true and proper earth- 

 currents, and neither in whole nor in any appreciable part have been 

 collected from the atmosphere, nor are due either in whole or in any 

 appreciable part to polarization imparted to earth-plates by the pre- 

 vious passage of earth-currents or of powerful telegraphic currents ; 

 nor are they due to any electromotive force in the earth-plates 

 themselves. 



llth. That the earth- currents in question (at least the powerful 

 currents present at all times of great magnetic disturbance) exercise 

 a direct action upon magnetometers, just as artificial currents con- 

 fined to a wire exercise a direct action upon a magnet. 



