igO ' SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. yo 



dotted lines show the corresponding' vahies with successive eleven- 

 year smoothing. 



Between several of these curves and the inverted sun spot curve 

 there is an extraordinary agreement. Particularly the curves for 

 the tropics, for North America, and in a less degree those for eastern 

 Asia are of this character. The variations in the curve for eastern 

 Asia appear to be displaced a couple of years in relation to the 

 sun spot curve. In general it holds that a maximum of sun spots cor- 

 responds to a minimum of temperature. The reader should note 

 that the scale of the sun spots increases downwards, while the scale 

 of the temperature curves increases upwards. 



The other curves show many small variations and in several cases 

 there is a strongly marked tendency to a half sun spot period in the 

 temperature variations. This is shown particularly well in the curve 

 for Russia where a minimum of temperature occurs approximately 

 at maximum of sun spots, but also a considerable minimum at the 

 minimum of sun spots. This is shown also in figure 65 which is 

 taken from Koppen's paper. The shorter periods are of course for 

 the most part removed from our curves in figure 66 in consequence 

 of the smoothing. 



In figure 67 we have compared the sun spot curve (S) with the 

 smoothed temperature curve for the whole earth (curve a) by con- 

 secutive three-years smoothing from the values given in Mielke- 

 Koppen tables. The agreement between these two curves is very 

 great and the existence of sun spot periods in the variations of the 

 air temperature upon the earth cannot be doubted. We have 

 studied the correlation between these two curves in this way: we 

 have determined the average temperature value which corresponds 

 to certain sun spot numbers. The means of these values we have 

 given in curve c in figure 67. This curve shows therefore the tem- 

 perature distribution which we should expect dependent upon the 

 number of sun spots. 



The difference between curve a and curve c is plotted in the curve 

 a-c which, however, shows considerable variations outside of 

 those which correspond to the simple sun spot period. As the reader 

 will perceive, there is a tendency in this curve to show two small 

 variations within each of the great simple sun spot periods. 



In order to pursue the question of what relation exists between the 

 variations of the sun and the meteorological phenomena upon the 

 earth, it is of importance to study the meteorological elements sepa- 

 rately. We have therefore collected a great series of investigations 



