1877.] the Rainfall with the Sun-spot Period. 255 



Table V. 





)f years' 

 vations. 



i rainfall 



whole 



riod. 



Average difference between mean rainfall of whole period of observation 

 and means of each year of cycle of eleven years. 







© o & 

 $1 



1st. 



2nd. 



3rd. 



4th. 



5th. 



6th. 



7th. 



8th. 



9th. 



10th. 



11th. 



Madras ... 



64 



in. 

 48-5 



in. 

 + 0-6 



. 



in. 

 +0-7 



in. 

 +9-8 



in. 

 +24 



in. 

 + 1-9 



~^n7 

 4-5-8 



in. 

 4-4-4 



in. 

 -3-4 



in. 

 -11-5 



in. 

 4- 0-7 



in. 



-135 



Bombay . . . 



52 



76-9 



o-o 



+4-1 



-11 



-2-4 



+ 11-2 



+2-9 



4-1-7 



+ 5-4 



- 5-8 



-10-8 



- 9-4 



Calcutta... 



47 



65-8 



+ 14-8 



-5-2 



-8-0 



4-1-5 



4- 4-6 



-5-3 



-03 



4-0-0 



- 50 



+ 1-8 



4- 1-8 



These results are entirely negative, and indicate no concordance among 

 the means of the several years of the cycle. The Bombay and Calcutta 

 observations, treated as those of Madras were, to ascertain the deviations 

 of individual observations from the successive means of the cycle, give 

 quite similar results. The deviations obtained for Bombay and Calcutta, 

 in the manner shown in Table II., are as follows : — 



Table VI. 





Average differences irrespective of sign between separate 

 observations and means of each year of cycle of eleven 

 years. 



Mean of 

 mean dif- 

 ferences. 



1st. 



2nd. 



3rd. 



4th. 



5th. 



6th. 



7th. 



8th. 



9th. 



10th. 



11th. 





in. 



in. 



in. 



in. 



in. 



in. 



in. 



in. 



in. 



in. 



in. 



in. 





7-1 



16-6 



5-5 



20-4 



20-8 



13-6 



6-7 



15-3 



9-6 



15-8 



6-4 



12-7 





7-9 



6-6 



7-1 



14-6 



12-3 



8-4 



7-9 



143 



5-0 



4-5 



5-1 



8-0 



In these cases, as in that of Madras, the mean deviation for the whole 

 eleven years of the cycle differs very little from the mean variation of 

 the single observations from the arithmetical mean of all of them, these 

 quantities being for Bombay 13*4 in., and for Calcutta 9*0 in. 



Although my special object in the present communication is to deal 

 with the alleged correspondence between the Madras rainfall and the 

 sun-spot periods, I have naturally turned my attention to Mr. Meldrum's 

 speculations of a similar character, and I have tested some of them in 

 the manner that I have just explained. 



Taking the Greenwich observations for fifty-five years, which will be 

 found at page 307 of vol. xxi. of the ' Proceedings of the Eoyal Society/ 

 in Mr. Meldrum's paper before noticed, and arranging them in the man- 

 ner shown in Table IV., the following results are obtained. The mean 

 rainfall for the whole period is 24-9 inches, and the entries are the 

 differences from this mean. 



