75 2 



BIRKELAND. THE NORWEGIAN AURORA POLARIS EXPEDITION, IQO2 1903. 



The two galvanometers were introduced as a shunt upon a circuit with a resistance of o- " 

 this arrangemement was employed the whole time. 



The earth-resistance was determined from time to time, and the following values were found' 



TABLE CXV. 

 Earth-resistances. 



The sensitiveness was determined in the manner previously employed, and the results v 

 follows : 



TABLE CXVI. 

 Scale-values for one millimetre deflection; unit volt per 400 m. 



The new instruments, it appeared, maintained a very constant zero-point, but, as the determinations 

 of sensitiveness show, the temperature-coefficient was comparatively high. 



The curves otherwise exhibit the same characteristic peculiarities as those previously found. 



We have here, too, determined the relation between a number of synchronous serrations. 

 will be seen from the following table, the conditions are very constant, especially as regards the first 

 three days. 



The numbers - - are given in units ~ . 

 zle millivolt 



The numbers for June 12 are perhaps not so valuable as for the other days; the small value 

 for the sensitivenes seems to indicate that contact-resistances have played a considerable part. 



