I go IllRKKI.ANI). TI1K NOKWKr.I AN ATROKA POLARIS KXPKDI T1ON, J 902 1903. 



The woiut scftimi, from 14'' o m to i8 h (I'l. XYIIl. 



(al 1 'lie conditions in northern latitudes. 



At Dvrafjord, beginning at 13'' 40, there is a rather long, not violent, but still considerable per- 

 turbation, which arts principally upon //, tending' to increase it. This condition lasts until the com- 

 mencement of the violent storm about i8 h 35"', and is continued for some time after the conclusion of 

 the latter at 22'' 15'". 



At Kaafjord the conditions are more variable, giving almost the impression of two separate storms, 

 the lirst with maximum at 14'' 45, the second lasting from i5 h 30"' until the commencement of the 

 great storm. All three elements are here about equally disturbed, // however most. 



At Axeloen the conditions assume the nature of a fairly long perturbation, which maintains more 

 or less the same character from 74'' o'" until the commencement of the great storm. The perturbation 

 is strongest between 14'' and 15'', and at about 18'' o" 1 . 



At Matotchkin Schar the conditions between 14'' and the commencement of the great storm, arc 

 very variable. They very much resemble those at Kaafiord. There is first a very well defined storm 

 between 13'' 45'" and 15'' 15'", with maximum at 14'' 35, after which, in the course of a few minutes, 

 comparative calmness, and then once more the storm leaps up with oscillations principally in the same 

 direction as during the first part of the perturbation. 



In connection with these conditions at the Norwegian stations, we will examine those at Sitka. 

 Here the perturbation is particularly powerful from 14'' 24'" to 15'' 45, the maximum being at 74 h 45. 

 Thus this storm commences during the same period of time, and has its maximum at the same hour as 

 the first powerful impulse, which was especially well defined at Kaafjord and Matotchkin Schar. We 

 find, however, that on the whole it apears somewhat later at Sitka. After this first powerful storm there 

 is comparative quiet, and then once more a slight perturbation appears, principally affecting //, and 

 lasting from j6 h 30 to i8 h . 



(b) 1 he conditions in loiter Intitudcs. 



In Europe the conditions assume the character of a lengthy perturbation, which begins to be par- 

 ticularly perceptible at about 13'' 45. In declination the conditions vary a good deal, the curve being 

 now above, now below, the normal line. In tin: horizontal intensity the conditions remain more constant. 

 All the time, until the powerful storm commences, there is an oscillation in II, answering to a diminution 

 there, this condition being also continued after the cessation of the powerful storm, and lasting until past 

 midnight. Here too we notice a particularly powerful perturbation with maximum at 14'' 42. This 

 augmentation occurs at the same time as the previously-mentioned, particularly powerful storm at the 

 northern stations. This characterisation of the conditions is also applicable to Tiflis, and indeed, especi- 

 ally as regards //, also to the district from Dehra Dun to Hatavia. 



At Dehra Dun there is quite a powerful perturbation in //. Here too 11 remains on the whole 

 below the normal, right up to the commencement of the great storm; and this condition continues after 

 the latter has ceased. In declination, especially as regards Dehra Dun, there are small oscillations 

 towards the east. 



At ( hristchurch also, perturbations occur throughout the period under consideration. In // the 

 conditions here are nearly the reverse of those at Dehra Dun, as // throughout has too large a value. 

 The already-mentioned perturbation with maximum at 14'' 45"' is very marked here too, and is quite 

 powerful both in // and in 1), and quite distinct even in / '. Here too its maximum is at 14'' 45; 

 but it is of shorter duration than in the northern hemisphere. 



There is some disturbance in the United States, but strange to say no particularly well defined 

 oscillations such as at Sitka anil the European stations. 



