PART III. EARTH CURRENTS AND EARTH MAGNETISM. CHAP. I. 75 1 



It would appear from the general survey map that the geographical conditions would favour such 

 . view. 



It will be seen that Bossekop is situated on a peninsula bounded partly by Alien Fjord with its 

 co arms, Kaafjord and Rafsbotten, partly by the comparatively broad mouth of the Alien River. 



The soil itself does not seem to contain any metal strata which would be more favorable to one 

 . rrent-direction than to another. 



On the border-line between land and sea, however, there will always, on account of the difference 

 the electric conductivity, be an unsymmetrical distribution of the earth-current density. 



If we look at the serrations at about 2 h i m and 2 h 8 m on the 313! March, we see that the direction 



the current at the first hour mentioned is more or less from N to S. At the same time there is a 

 i.i-rosponding force westwards in D, and in V a force vertically upwards. This last might indicate 



at the main body of the current was situated to the west of the place, i. e. out in the fjord; but it 

 ight also be imagined to be produced by currents in the east that had a contrary direction, a 



indition of things that would not be impossible. To decide this question, simultaneous observations 

 ith short cable-lengths at various places is required. 



If we assume that the first alternative is correct which the greater conductivity of sea-water as 

 "iiipared with soil perhaps makes probable it might seem remarkable that in Kaafjord the main body 

 ' the current is found in the land and not in the sea. 



In reality, however, this is easily explained, as the upper branch of the Kaafjord, which lies near 



ir observing-place, is connected with the lower fjord only by a very narrow channel, while the Bossekop 

 ninsula is surrounded by the great, wide Alten Fjord. 



In the case of the second deflection at about 2'' 8 m , the deflections in the magnetic curves are 

 versed, as also in the N S curve. We find, moreover, a distinct current-component in a direction W E. 

 The direction of the current is thus now more or less SW NE. 



The same two alternatives may also be employed for the explanation of this phenomenon. It is 

 oubtful which of the two is to be preferred; perhaps they act in concert. 



OBSERVATIONS OF EARTH-CURRENTS AT KAAFJORD, MAY 1910. 



152. During the expedition which I, accompanied by Mr. KROGNESS, made to Kaafjord at the time 

 passage of Halley's comet across the sun's disc in May, 1910, we also, as has been stated, took 

 jservations of earth-currents with earth connections, as far as possible in exactly the same places as 

 1902 03. 



The arrangement was the same as at that time, but for reasons already touched upon, we inserted 

 each of the earth-connections a great resistance. 



As the galvanometers previously employed had proved to be rather too sensitive, and, more parti- 

 ilarly, to have no constant zero-point, we used, in their stead, two new school-instruments from 



DELMANN. 



In the N S line, the resistance added was 55 300 Q, and the galvanometer employed which I 

 ill call a - had an internal resistance equal to 152 Q. 



In the E W line, the resistance added was 53000 2, and the galvanometer b had an internal 

 -sistance equal to 187 SJ. 



The galvanometers a and b were set up at respective distances of 172 cm. and 115 cm. from the 

 ?gistrator-cylinder. 



