PART II. POLAR MAGNETIC PHENOMENA AND TERRELLA EXPERIMENTS. CHAP. V. 65! 



45 m . In the above-mentioned band in the north, a little lower, occurs a very marked, evenly 

 nldish light. The highest point of the band is in a direction N 35 E. 



48'". Several evenly bright bands in the form of great circles converging towards a point on the 



1 rizon in a direction about S 45 E. 



To the south many fine, awl-shaped stripes massed more or less in bands. 



ii h 51"" p. m. Dark cumulo-stratus rising in the west and hiding the cirrus clouds. In the south 



II many threadlike bands " 



The above extracts are sufficient for our present purpose. The observations were continued 

 t niighout the night, with interruptions occasioned by the overclouding of the sky. 



The following accounts of exactly similar observations, made at the same hour 8.30 p. m. on the i8th May, in the 

 ti n of Tonsberg, and at Blakjer, about 90 kilometres north-north-east of Tonsberg, read almost like a fairy-tale. 



The account from Tonsberg was given by the magistrate of that town, his wife and son, with a statement of their readi- 

 n!s to confirm by oath what was written. At Blakjer the phenomenon was observed and described by several trustworthy 

 p ^ants without any knowledge of what had been seen in Tonsberg. 



The magistrate's account is as follows: "We were all three walking along the quays. The sun was near the horizon, 

 a we saw suddenly appear round it a number I suppose from 50 to 100, possibly more of dark (blackish grey) circles about 

 at arge in diameter as the moon, and these then spread out on both sides of the sun". 



The people at Blakjer saw at the same hour, in the direction of the sun, bubbles the size of a child's head and smaller 

 siJenly descending towards the earth, shining in all the colours of the rainbow. 



It is not, of course, easy to say what has caused the unusual phenomena here observed, but it can only be supposed 

 tl there have been certain foreign bodies in front of the sun that have produced the various light-effects. 



The magnetic registerings in Kaafjord were begun on the 7th May and continued by us until the 



2 1 June, after which date they were carried on more or less completely by Herr L. HEITMANN until 

 tl middle of July, in order that a general idea might be obtained of the course of the variations through 

 a .eriod of some length. 



In addition to the ordinary slow-run registering-apparatus, we also took with us one for quick-run 

 re isterings. The latter were begun on the i8th at about 4 a. m. Gr. M. T., and continued until about 



3 . m. on the 2oth. 



During the same period, magnetic registerings were also undertaken at Teisen near Kristiania, by 

 HT O. DEVIK. 



The special interest of these observations, and our reason for mentioning them here, is the con- 

 mtion that their results may be supposed to have with the passage of the earth through the 

 'I- ict's tail. 



With regard to the magnetic curves, this period may be characterised as follows: The period from 

 th yth May until noon on the i8th was fairly quiet magnetically, the storms that occurred being of 

 co paratively little strength. 



At about i p. m. on the i8th May, an unusually powerful magnetic storm suddenly began, devel- 

 op ig in the afternoon into a positive polar storm, then changing later, and appearing in the evening 

 ;m night as a negative polar storm. 



From about 4 a. m. on the igth, the storm decreased in strength, and at about 6 a. m. the con- 

 tiitms were once more quiet, and continued so for some days. 



On the 24111, at about 9.30 a. m., an unusually powerful magnetic storm occurred once more, with 

 a mrse similar to that of the storm of the i8th igth May, but of somewhat longer duration. 



As the passage of the comet was to take place on the morning of the igth, it seemed reasonable 

 at rst sight to suppose the storm of the i8th igth to be caused by the comet. Just at this time, 

 li'x-ver, matters were complicated by the appearance of a large group of sun-spots near the sun's cen- 

 tra meridian. These too, then, might be the cause of the storm, as in its main features the course of 

 tin perturbation was like that of ordinary perturbations. 



