in relation to the Solar Spots. 441 
West Florida; group VII comprehends the sea-coast from Vir- 
ginia to Florida, and group VIII includes the sea-coast of Cali- 
ornia. 
In these groups the percentage of the mean amount of rain- 
fall is tabulated for each year of observation, the longest period 
of record extending from 1804 to 1867. 
From the data thus afforded curves are constructed which 
present to the eye the annual fluctuations of the rainfall over 
the vast region embraced by these groups. Mr. Schott speaks 
briefly of the connection between the solar disturbances and 
the rainfall, stating that the rain curve for 1837-8 shows a de- 
cided minimum in precipitation, when there was a marked 
maximum of solar activity; but that the two phenomena lead 
to an opposite conclusion about the epoch of 1855-6 ; a mini- 
mum of rainfall then occurring with a minimum extent of sun- 
spot area. He does not enter into any detailed investigation of 
this supposed connection. : 
Under these circumstances, it appears, therefore, desirable, in 
order to detect what connection, if any, exists between the fluc- 
tuations of the annual rainfall and the variations in the extent 
of the solar spots, that these phenomena should be compared 
either year by year, or by groups of years; and this it is now 
proposed to do. 
Taking Dr. Wolf’s table of the relative extent of sun-sp 
for each year, within the period from 1804 to 1867 inclusive, 
in which period the yearly percentage of the average rainfall is 
also given in Mr. Schott’s table of territorial groups, two 
methods of comparison can be employed if we wish to ascer- 
tain whether an annual excess of sun-spot area is attended by 
an excess of annual rainfall, and vice versa. The first mode is 
each side of the minimum year for a minimum set; or where 
this is not possible, a triennial group is formed. 
