73 



those of Airy) showing only the differonce between the re- 

 salts of the two stations. 



l:o ,,The earth-currents appear in short lincs (1 km) 

 generativ not as a current going constantly in a certain di- 

 rection with slowly varying intensity, but in form of alter- 

 nating currents of different strength, changing, even rapidly, 

 their direction". 



In Sodankylä about 7° to the north from Pawlowsk, 

 the statement vvill be: that the earth-current often appears 

 in lines of 5 km as going in the same direction but of 

 rater variable strength and by and by in form of atternating 

 currents. 



2:o „The component of the earth-current which ap- 

 pears in the E — W line is in general stronger than that in 

 the S — N line; the direction of the current approaches more 

 the parallels than the meridians". 



This statement is also valuable for Sodankylä, but it 

 must be added that the direction depends also of the sea- 

 son and of the year, because the inequality between two 

 years can be very great. 



3:o ,,The daily variation is not well marked in every 

 separate day of the ,. jours termes" but when the average 

 of all the 24 days is taken, a daily variation is well mar- 

 ked with a value of 0,0008 volt". 



A comparison between the results of Pawlowsk and 

 Sodankylä shows well the difference. For Sodankylä the 

 comparison must be limited to the E — W current only. 



Max. Min. Amplitude. 



The current S— N 4 h — 5 h a. m. 8 h p. m.) 



„ „, ... ,,, } 0,ooo8 Pawlowsk. 



E-W 8 h „ l 11 „ J 



E— W 7 h „ 9 h a. m.| 



nh _. ) 0,0 6oo Sodankylä. 



„ „ 6 h p. m. ll h p. m.J J 



We see then here a great difference regarding the 

 course and the amplitude, which is 75 times greater in So- 

 dankylä than in Pawlowsk. 



