226 B1RKKI.AND. THE NORWEGIAN AURORA POLARIS EXPEDITION, 1902 1903. 



The great difference in the effects of the force at Bossekop and Sodankyla is characteristic. At 

 the latter station the forces are on an average only about one quarter of those at Bossekop. As these 

 stations are situated very near to one another, it may be concluded that the acting systems come fairly 

 close to the last-named. 



The conditions at Little Karmakul during this period are particularly interesting and peculiar. This 

 station is situated, as will be seen, upon the boundary between the two districts of precipitation ; to the 

 east and north we come upon the negative polar storm, to the west there is the positive. It would 

 therefore be natural to suppose that at this boundary-station, both these systems would act; and this 

 proves to be actually the case. 



In both the areas of precipitation, the positive as well as the negative, the deflections in horizontal 

 intensity continue to be in one direction as long as the storm lasts. At Little Karmakul, on the other 

 hand, the conditions are different; at one time there are wide deflections in the positive direction, at 

 another wide deflections in the negative direction, and again smaller deflections up and down about the 

 normal line. It thus appears from a direct consideration of the curves, that we now have a direct effect 

 of the positive system, and then of the negative, and now again the two systems neutralise one an- 

 other's effect. 



Altogether analogous, although less marked, conditions are found in Jan Mayen, where at first the 

 positive system acts almost exclusively, then mainly the negative, but only in a series of brief impulses, 

 after which the horizontal-intensity curve returns once more to its normal height. As regards declination 

 the conditions are somewhat similar; but there it is not possible to determine so directly which system 

 it is that is acting at the various times. 



At about 23'', the perturbations are ended at almost all the stations, and after that time it is only 

 at two or three places that perturbing forces of any special magnitude appear, and these should pro- 

 bably be regarded as more local. 



Six charts have been drawn up for this period, representing in all 17 epochs, by means of which 

 the course of the perturbations may be followed from hour to hour. 



Similar fields in the main are found upon the various charts, only displaced to some extent from 

 time to time. 



Chart III; time 14'' 20'", //'' 2o m and i&> 20 m . 



At the first-named hour there are more or less powerful forces only in the district about Jan 

 Mayen, Cape Thordsen and Ssagastyr; and the current-arrows there are directed eastwards. It is impos- 

 sible to decide from the charts whether this is a connected system or not. The curves seem to indi- ' 

 cate, however, that it can scarcely be an entirely connected system. 



Nor has the perturbation developed any special power at 15'' 2o m ; and at Ssagastyr, and Cape 

 Thordsen, the earlier perturbing forces have almost entirely disappeared. In Jan Mayen only is there 

 still the effect of the positive system. 



It may even now be worth while to notice the conditions at Godthaab and Kingua Fjord. At these 

 two stations we now have arrows that point in exactly the opposite direction; at one place a positive 

 storm is evidently acting, at the other a negative, and it would thus seem as if the boundary between 

 two such tracts just chanced to be between the two stations. This is a condition with which we shall 

 subsequently frequently meet, and which we therefore at once point out. 



We thus again meet a peculiarity in the state of things in Kingua Fjord, and further on we will 

 have an opportunity of also coining in contact with other cases diverging somewhat from what we find 

 at the other stations. It might therefore be well to examine here at once what might be supposed to 

 be the natural reason. 



