168 ANNAL& NEW YORK ACADEMY OF SCIENCES 



Temperature Variations at Stockholm axd Batavia 



In a recent publication,^^ Axel Wallen gives the curve of the consecu- 

 tive annual means of temperature observed at Stockholm, for the entire 

 series of observations extending from 1756. A comparison of his curve 

 with the Batavia curve which I published some years ago shows that they 

 are very much alike. The monthly departures of Stockholm^^ present 

 also many striking analogies with those of Batavia. ^^ It would be worth 

 while to make a more detailed examination. 



The variations at Stockholm and Batavia seem to be in perfect har- 

 mony : a crest of the Stockholm curve corresponds nearly to each crest of 

 the Batavia curve, and the intervals between corresponding crests are 

 approximately the same. It will be necessary to find many more such 

 similar curves, belonging to far distant stations, before the main con- 

 clusion which might be inferred from the comparison of the Batavia and 

 Stockholm curves will have the practical value one might expect. 



Batavia being in advance of Stockholm, it is easy to understand that, 

 taking seasonal departures — as Hildebrandsson, Mossman and others have 

 done — correlations between these two stations have to be found. But 

 these correlations will evidently be simply apparent correlations. It is 

 not because a given season of the year is abnormally warm in Batavia, 

 that the following season has to be exceptionally warm in Stockholm and 

 so on; but it is because the same pleionian variation appears with the 

 same regularity in one place as in the other, but slightly retarded, that a 

 seasonal correlation between the two places must exist. The Batavia and 

 Stockholm curves give, therefore, a plausible explanation to the so far 

 unexplained correlations between seasonal departures of distant stations. 



Coming back to the volcanic dust problem studied in this paper, it is 

 important to notice that the Stockholm curve seems to be more complete 

 than the Batavia curve. The pleion of 1883, which on the Batavia curve 

 has been greatly reduced by the dust veil effect, is very much better 

 developed on the Stocldiolm curve. In a similar way some apparent 

 anomalies on the Batavia curve may be considered as being really anom- 

 alies which would not exist if the curve were perfectly developed as it 

 ought to be. For example, the portion of the consecutive temperature 

 curve of Batavia from 1871 to 1873 is abnormal. Likewise, the long 



^ Axel Wallex : "Flerariga variatiouer hos vattenstandet i Malaren...," Meddelan- 

 den fran Hydrografiska Byran : 4. Stockholm, 1913. 



°^ H. E. Hamberg : "Moyennes mensuelles et annuelles de la temperature. . .a robser- 

 vatolre de Stockholm." Konigl. Svenska Vetenskaps-acad. Handlingar, vol. 40, no. 1. 

 Stockholm, 1906. 



*- Observations made at the Royal Magnetical and Meteorological Observatory at Bata- 

 via. Vol. 28, p. 108. 1907. 



