l8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 68 



Buenos Aires during the summer of 1913. The departures of the 

 temperature from the daily normals of 50 years for 184 observations 

 in June, July and August (92 days) were correlated with the tempera- 

 ture departures occurring three days later, four days later, etc., up 

 to 30 days later. 



These computations were made nearly a year preceding the recep- 

 tion of the solar data. 



The curve derived from the computed correlations is very regular 

 and is very simliar to the curve drawn from the mean of each con- 

 secutive five of the solar factors. In the temperature curve the chief 

 maximum is on the 22d day of the period and has a value of .25 with 

 a probable error of ± .047. In this case the correlation factor, while 

 not large, is more than five times the probable error. The data 

 entering into this latter curve were computed earlier than those 

 entering on the solar curve, and its close resemblance to the mean 

 solar correlations, shown by the broken curve in figure 3 is another 

 proof of the connection between solar changes in radiation and 

 terrestrial meteorological changes, and is also a proof of the reality 

 of a period of about 22 days. 



This period is shorter than the period ordinarily assumed for a 

 solar rotation and leads one to suppose that it has some other origin. 



SUMMARY 



Two important conclusions are derived from this study : 



( 1 ) That there is an intimate relation between solar changes and 

 meteorological changes of short period, and that measurements of 

 solar radiation like those made by Dr. Abbot and his associates have 

 the greatest importance for meteorology. 



(2) That there is a class of meteorological changes which have 

 their origin in equatorial regions and by a transference of air, prob- 

 ably in the upper layers, are felt within a few days in higher latitudes. 

 These changes are the complement of the complex meteorological 

 drift which goes from west to east in temperate latitudes with a 

 component of motion from pole to equator in both hemispheres. 



