370 



SCIEISITIFIC RECORD FOR 1884. 



359. A. Paulsen, of Copeubagren, givos in Xature. xxix, p. 337, the 

 results of observation on the height of the aurora as made at Godthaab, 

 of which the following notice appears in the Au&«trian Zeitacliri/t fur 

 Meteorologie : 



The results of observations at that station on the altitude of auroras 

 were as follows : 



Of the latter 14 cases the lowest were, respectively, 3.72, 3.69, 3.22, 

 2.87, 1.99, 1.96, 1.35, 0.61. 



360. Prof. H. Fritz, of Zurich, states that as these observations were 

 very carefiill}' made, the distance befeween the two observers being 5.8 

 kilometers, they seem especiallj' worthy of study, and undoubtedly 

 confirm the observations of S. Fritz, made at Ivigtut, and those of 

 Steeustrup, made in Iceland, and assure us that undoubtedly the 

 auroral light may exist even at the ground. He has therefore at once 

 collated all previous records of low-lying auroras, and makes some 

 general remarks upon the present state of our knowledge with regard 

 to these and the character of the observations still needed to further 

 elucidate the subject. {Z. 0. O. M., xix, p. 290.) 



361. Prof. H. Fritz, in a general review of Tromholt's Xordlysets 

 Perioder and of Eubenson's Catalogue of Swedish Auroras, finds that 

 the 111-year period, first determined by him in 1802 and confirmed by 

 Loomis for the American auroras, is also strongly confirmed by Euben- 

 son's catalogue. He also finds that the influence of the bright light of 

 the moon in introducing an ai)parent lunar period, as first shown by him 

 in 1864, is fully confirmed by Tron)hf:)rt fro-m the study of observations 

 at Godthaab and Christiania. {Z. 0. G. ]\J., xviii, p. 321 ) 



362. Prof. Sophus Tromholt, in his " Om Xordlysets Perioder," pub- 

 lished by the liistitut IMet. Hanois, deduces the following conclusions 

 from the observations of the aurora made at Godthaab, in Greenland, 

 during 1805 to 1880 by Professor Kleinschmidt : 



1. Everything ])ertaining to the va'iable frequency of auroras in 

 Godthaab proves that the phenomenon exists there under quite different 

 conditions from those obtaining in lower latitudes. 



2. The number of observed auroras is inversely proportional to the 

 square root of the cloudiness. 



3. After correcting for cloudiness there remains not only no parallel- 

 ism between the sun-spots and the auroras, but even an almost diamet- 

 rical difference as to frequency. 



4. The maximum of auroras is delayed two years behind the minimum 



