1 52 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 70 



the lines on which we interpret the connection of temperature varia- 

 tions with variations of solar activity we think that there is a 

 natural explanation and we shall later return to it. 



Bigelow sums up the temperature anomalies without regard to 

 sign for the 26.68 day period for each year for his series 1878 to 

 1893, and obtains values which he calls temperature amplitude and 

 which give in a fashion the degree over which the temperature varies 

 within this solar rotation period. The curve which exhibits the 

 variations found in this way agrees excellently with the curve for 

 the magnetic elements in Europe and partly with the curve for the 

 sun spots. In this way he shows that increased magnetic activity 

 within the solar rotation period is associated with increased tem- 

 perature variations and the opposite. 



The mean yearly temperature for thirty meteorological stations 

 in the United States varies as Bigelow finds for the period 1878 to 

 1893 oppositely with the magnetic elements and oppositely also with 

 the sun spots. This he thinks is in agreement with his theory on 

 the anti-cyclonic and cyclonic circulations which according to him 

 vary directly with what he terms the " solar magnetic radiation." 



Later Bigelow continued his investigations on the dependence 

 between the meteorological variations and the solar activity and 

 was confirmed in his first conclusion that lowering of the temperature 

 in the United States attends an increase of the " solar magnetic 

 intensity " and vice versa. This holds not only for the longer periods 

 of eleven years, but also for short periods of two and three-fourths 

 years which he found in 1898 and of which there are four within 

 the eleven-year period. 



He extended his investigations to a great number of stations in 

 different parts of the world for the time 1873 to 1900 and took 

 into consideration also the variations in the solar prominences as 

 given by Lockyer in his paper 1903. Bigelow finds in the tempera- 

 ture variations a more or less distinct period of about three years. 

 But the variations within this period behaved differently in differ- 

 parts of the earth. This the Lockyers also found for the air pres- 

 sure. Bigelow distinguishes between three types of curves for the 

 variations : 



1. The direct type, where the temperature variations go the same 

 way as the variations in the number of the prominences. 



2. The indirect type, where the variations in the temperature go 

 in opposite directions to those of the prominences. 



3. The indifferent type, when the temperature variations have 

 no satisfactory agreement with the variations of the prominences. 



