238 
POPULAR SCIENCE REVIEW. 
conditions, it is difficult to believe that the subject can be satis- 
factorily settled. This uncertainty, however, does not much 
affect the present paper, the object of which is, not to find out 
either the origin or formation of the spots, but to ascertain 
whether the presence of greater or less numbers of spots on the 
surface of the Sun affects our atmosphere in such a manner as 
to cause a more or less marked periodicity in our climatic 
changes. 
In Ceylon, the variation of the rainfall, and consequently of 
the cereals, in direct ratio with the spots, has become a matter of 
popular observation; but so far as we know, this is the only part 
of the Earth’s surface in which the variation is so noticeable. 
Lying as Ceylon does, almost under the equator, it is of course 
there that we should expect to find any changes occasioned 
by alterations in the amount of solar radiation exceedingly 
strongly marked, and that this is the case is a great argu- 
ment in favour of the upholders of the Sunspot theory. In Mr. 
Blanford’s Vade Mecum, where rainfall and Sunspots are investi- 
gated with a minuteness commensurate with the importance of 
the subject to the Indian community, the rainfall of a long series 
of years is given for six important Indian stations. This series 
is subdivided into eleven-year periods, and the average rainfall 
of each of the homonymous years being taken, the difference of 
each average year is shown as a percentage of the local mean 
of each station, and in a second table as a percentage of the 
mean rainfall of all the six stations. The latter table, more 
particularly when the amounts have been smoothed down by a 
process which will be explained fully later, shows a very dis- 
tinct variation in the amount of rain, a decided excess in years 
of Sunspot maximum, and a decided deficit in those of Sunspot 
minimum. The following figures, copied from the Vade Mecum , 
show the rainfall for Madras, and it is impossible to deny that 
there is very strong evidence of a connexion between the two 
phenomena of precipitation of rain and of the presence or 
absence of spots on the surface of the Sun : — 
Year. 
Inch. 
1860, &c. . 
+ 8*5 
per cent. 
1861 „ . 
+ 6*2 
» 
1862 „ . 
+ 9-2 
tt 
1866 „ . 
+ 5-8 
tt 
1864 „ . 
- 71 
if 
I 860 „ . 
- 13-2 
ft 
1866 „ . 
- 12-7 
tt 
1 fc67 „ . 
- 140 
tt 
1868 „ . 
- 60 
tr 
I860 „ . 
+ 6-0 
tt 
1870, &c. . 
+ 11*7 
tt 
