Solar Clianfjes of Temperature and Variations in Rainfall. 417 



by an upper S.W. current,* their incidence is very different and their 

 inclusion might mask the events it was most important to study. 



The first investigation undertaken was the study of the rainfall 

 tables published by the Meteorological Department of the Government 

 of India. These were brought together by Blanford down to the 

 year 1886.1 As the widened line observations were not begun at 

 Kensington till 1879, the discussion was limited in the first instance to 

 the period 1877-1886 inclusive, embracing the following changes in 

 solar temperature, occurring, as will be seen, between two conditions of 

 mean solar temperature : 



Bearing in mind that the intensity of the + pulse may in some 

 measure be determined by the solar disturbances, which for the present 

 are registered by spotted area, it is important to point out that the 

 preceding maximum in 1870 was remarkable for obvious indications of 

 great solar activity.:}: 



It soon became evident that in many parts of India the + and - 

 conditions of solar temperature were accompanied by + and - pulses 

 producing pressure changes and heavy rains in the Indian Ocean and 

 the surrounding land. These occurred generally in the first year 

 following the mean condition, that- is in 1877-8 and 1882-3, dates 

 approximating to, but followed by, the minimum and maximum periods 

 of sun-spots. 



* ' Report,' 1877, p. 125. 



t ' Indian Meteorological Memoirs,' vol. 3. 



" The year 1870 was characterised by an exuberance of solar euergy, which ii* 

 without parallel since the beginning of systematic observations (i.e., since 1825). 

 The number of observed groups far exceeds that of any previous year, and it 

 appears also from a cursory comparison witli the maximum year's observations, as- 

 recorded by Hofrath Schwabe, that the magnitude of the different groups, as well 

 as the average amount of spotted surface during any period of the year, is- 

 unprecedented." (' Monthly Notices,' vol. 31, p. 79, Warren de la Rue, E. Stewart, 

 B. Loewy.) 



The table which the authors of this paper give shows that during the year, 

 although observations of the sun were made on 213 duys out of the 364, there was 

 no day without spots recorded. In fact, during the whole year no less than 403 

 new groups of spots were noted, thus showing us that on the average there was 

 more than one new group per diem. 



The authors further remark. "A very remarkable feature of the groups 

 observed during the year appears to be their extraordinary lifetime ... an 

 exceedingly large number of groups completed three, four, and even more revolu- 

 tions before finally collapsing." 



VOL. LXVII. 2 H 



