210 HIUKll-AM). Till: .XORWFC.IAN AfROKA POLARIS EXPEDITION, 19027903. 



There is much resemblance between this lirst section of the perturbation and that of the whole on 

 the 1 5th February, which is -worthy of notice, and is immediately apparent on looking at the curves. 

 They also both occur at about the same time ol day. 



At Sitka the two perturbations resemble one another also in detail. On both days the rendi- 

 tions are those of two separate perturbations, each of about the same duration and following the same 

 course, and each with a wcll-dclined maximum. The chief difference is that the perturbation of the 151!) 

 February occurs on the whole about 40 minutes later in the day. The resemblance extends still farther, 

 lor about three hours before this perturbation, there are on both days two fairlv powerful and well- 

 defined, but brief perturbations; but the perturbation occurring at about midnight on the 2yth October 

 has no parallel on the 151!) 1-ebruarv. 



The resemblance is not, however confined to Sitka. Both in Furope and India, the conditions 

 exhibit surprising points of similarity. If we look, for instance, at the curves for Tiflis, we find on both 

 days a long perturbation answering to a perturbing force towards the south and south-east. This is inter- 

 rupted by another perturbation of short duration, which represents a perturbing force directed towards 

 the north-east; and in both cases this occurs simultaneously with the latter of the two almost separate 

 storms at Sitka. 



The curves for the Norwegian stations also exhibit some similarity. At A.xeloen there is the distinct 

 effect of the system that forms the first perturbation at Sitka from 13'' to 14'' 45; this however pos- 

 sibly does not appear so distinctly from the copied curves, as these lirst begin at that time when the 

 perturbation has re-ached its maximum. After this perturbation the intermediate storm commences with 

 a strength, which relative to the preceding storm and to the storms on the other Norwegian stations, 

 forms a good analogy to that taking place on the 151)1 February, 1903. 



The perturbation of the 1 5th February has already been described at length, and most of the 

 remarks there made with regard to the theory of the perturbation may be applied to the present case: 

 On the whole also we find a good correspondence with the conditions for the 8th February but the 

 details that day are here not quite so striking resemblant as on the i5th. 



As on the '5th February, the distribution of force be-fore and after the intermediate storm is about 

 the same. This section ot the perturbation therefore divides into two parts, 



(1) the long storm, and 



(2) the brief, intermediate storm. 



The field during the long storm is shown on Churls I, II and ///at 14'', 15'' and 15'' 30 and 

 alter the intermediate storm on L'lnni III at 17''. Here too, it shows as a whole the very same con- 

 ditions as the field on the 151)1 February. 



The current-arrow at Kaafjord and at Matotchkin Schar is directed eastwards on the whole, while 

 that at Axeloeii is directed westwards. Also the same conditions which we have found (see p. 191! 

 with the previously described storms which appear at this time of day. Farther south in Furope, the 

 current-arrows also point in a westward direction. There is also the remarkable circumstance that the 

 force increases southwards from Stonvhurst and Kew. At 1'awlowsk, the force before the intermediate 

 storm is almost insensible, whereas in the district between Tillis and Batavia it is very strong, and 

 strongest of all at 1 >ehra Ihm. In the United States the direction of the current-arrow is NNW. At 

 Sitka the current-arrow has a typical direction, north-west. At Honolulu the conditions are very quiet 

 during the whole twenty-four hours. 



It thus appears that the strong effect found in the south of Asia is not limited to those regions only, 

 but does not extend round the equator. We see that as on the 151)1 February, North America and 

 Europe constitute an area of divergence ol the perturbing force. The neutral point should be situated 



