234 



PROGRESS OF METEOROLOGY m 1889. 



a rapid increase; in the months from November to February a maximum 

 is reached at 7 p. m., while from March to May the maximum occurs at 

 about 7 A. M.; but the curve from 8 p. m. to 7 A. m. is high and has but 

 little rise. From June to October there are two maxima, one at 8 A. 

 M., the other at 8 p. m. 



Periodicity of temperature.— lu the treatment of the mean daily tem- 

 perature curves at polar stations, Prof. H. Fritz has perceived a regular 

 sequence in the maxima that seems to him to be not purely accidental. 

 By placing together the maxima at Jau-Mayen, Godthaab, Fort liae. 

 Uglamie, Vivi on the Congo, and Zurich, he has derived a 13.84-day 

 period, or better, the half of a 27.687-day period. This agrees almost 

 exactly with the period of suuspots and auroras (see Fritz ; Das Polar- 

 Ucht, p. 206), as well as with the period found by Buys Ballot from the 

 temperatures at Zwauenburg, Harlem, and Danzig. 



For further proof of the reality of this period, the observations of 

 Kane iu Smith's Sound, of the second German North Polar expedition 

 to Sabine Island, and of other arctic observers arp reduced to the same 

 period and compared with the maximum of sunspots. These data also 

 show an agreement. 



Temperature anom,aly — Dr. Hellmann calls attention to the long-con- 

 tinued temperature anomaly which has prevailed over Germany and 

 other neighboring countries of western Europe from the beginning of 

 1885 to the present time (April, 1889). By means of graphic charts of 

 monthly temperature he shows that the temperature iu western 

 Germany has for the most part lagged behind the normal. In Loningen, 

 of the fifty-one mouths from January, 1885, to March, 1889, 71 per 

 cent, have been too cold. Previous cold periods have occurred in the 

 years 1835-'38 and 1784-'87. {iMeteorologische Zeitschrift, vr, p. 275.) 



Secular variation of temperature. — Mr. William Ellis has tabulated 

 and discussed the temperature observations made in England from 

 1849 to 1888 with the following results : 



{Quar. Jotirn. Roy. Met. Sac.) 



