PHYSICAL AND METEOROLOGICAL RESEARCHES, PRINCI- 

 PALLY ON SOLAR RAYS, MADE AT THE STATION 

 OF AGRICULTURAL CLIMATOLOGY AT 

 THE OBSERVATORY OF JUVISY. 1 



Camille Flammarion, 

 Director of the Station. 



THE SUN AND THE TEMPERATURE. 



There appears to be a very curious relation between the annual tem- 

 perature and the variation of the sun spots, which seems to indicate a 

 certain correlation between the two phenomena. It is known that in 

 the manifestation of its activity the sun exhibits a certain periodicity; 

 there are dark spots, facuhe or illuminated spots, and eruptions. This 

 period is about 11 years. The last maximum occurred in 1893 and cor- 

 responded with the maximum temperature, not only in France, but in 

 many other parts of Europe. The last minimum occurred from 1887 to 

 1890. This corresponded with a series of cold years. Below is given 

 the extent of the spotted solar surface in millionths of the visible solar 

 hemisphere, calculated from data collected at Greenwich, Dehra-Doon 

 (India), and the island of Mauritius, and the average temperatures of 

 each year in Paris. 



Belation between nun spots and temperature. 



The data are shown graphically in fig. 5 (see p. 204). 



By adding the years by couplets the effects of local disturbances and 



1 Continued from page 114. 



203 



