648 I5IRKELAND. THE NORWEGIAN AURORA POLARIS EXPEDITION, igO2 1903. 



Mr. G. R. HUGHES, of Pretoria, sends the following report: 



.... "The Moon, which was in its second quarter, was surrounded by a ring which had a me- 

 tallic appearance. It was of considerable diameter and, to my recollection, the inner edge of the ring 

 (nearest the Moon) was yellowish (the yellow of the Sun), then merging into a dirty brown. The outer 

 edge was dull grey, like the clouds, that covered the sky. The ring appeared to have walls, if one may 

 so distinguish from a 'flat' surface. It was exceptionally well-defined. I observed the phenomenon until 

 nine o'clock, when I ceased to give it attention and am unable to say when it finally disappeared. 



"One remarkable phase was an inner ring which manifested nothing metallic. It was faint and 

 flat in contra-distinction to the outer and larger ring. The inner ring was dull grey in colour. 



"The Moon on the night of the igth May was again surrounded by a ring; the latter was much 

 more clear-cut that on the previous night. There were less clouds in the sky. When I first observed 

 the Moon between 6.30 and 7 p. m., it was clear of the clouds and had no halo. It, however, appeared 

 to be less distinct than usual. The features on its surface were not so sharply defined; while no haze 

 was visible to the eye, I am confident that some influence was present in the atmosphere. I tried a 

 view with binoculars, but still the features lacked sharpness in definition. As the Moon approached tin 

 clouds, which previously were scattered, they seemed to break, and I saw the ring evolve. The area 

 within the ring, unlike the previous night, was clear of cloud. The ring was decidedly metallic in 

 appearance, but I did not observe so much yellow colour as on the i8th. My note reads: 'Moon sur- 

 rounded by ring of dark brown material'. I observed the phenomenon for half an hour. The weather 

 conditions at the time were restful, but later in the evening the wind arose." 



Dr. FRANZ LINKE writes in a preliminary statement in "Meteorologische Zeitschrift", June, 1910: 



"The Meteorological Geographical Institute of the Physical Association at Frankfurt a. M. had 

 erected by May I2th a temporary observatory on the Feldberg in the Taunus (880 m.), where arrange- 

 ments were made for atmospheric-electric and terrestrial-magnetic registerings and observations, the 

 results of which will be published later. At present, attention will only be drawn to the quite abnormal 

 phenomena. Since the I2th May, we have had high-pressure weather; an evenly warm, dry current 

 of air out of the eastern continent continued uninterruptedly, and apart from some thunderstorms, brought 

 continuous warm, clear, summer weather. 



Only on the afternoon of the igth, a few hours, that is to say, after the passage through the 

 comet's tail, there occurred a remarkable cirrus-overclouding with lunar halo and ring, which, if it 

 had been observed in an ordinary way, I should have ascribed to the influence of the ions expelled 

 into the atmosphere. I did not, it is true, even at 2 p. m., at a height of 8500 m. notice anything ol 

 these ions; on Gerdien's conductivity-instrument, a strong, but for such heights not abnormal conductivit 

 was observed. 



The same evening there first appeared the following abnormal twilight phenomena. In the south- 

 ern sky a broad, reddish yellow stripe extended southwards from the sun more than 100. 

 north there was nothing similar to be observed. On Friday evening, however (May 20), a similar 

 luminous band, about 10 in width, and of the same horizontal extent, appeared on the northern horiz< 

 The twilight had also all the characteristics of the disturbance, such as a Bishop's ring, a reddish brown 

 colour, unusual clearness and duration. In the course of the next few days, from the 2ist to the 24th 

 May, the clear light in the north constantly spread over the entire sky; not until the 24th was the 

 twilight symmetrical with the sun. 



If we make the cosmic dust of the comet's tail expelled into the earth's atmosphere, responsible 

 for the twilight anomaly, we must assume that on the day of the transit, Thursday, the igth May, 

 principally in the equatorial regions, the cosmic dust reached the strata in which the twilight is found 

 (a height of from 10 to 20 km.). It must however quickly disperse or fall upon the earth. Great quan- 



