THIETY YEAES’ EAINFALL AT CLIFTON. 
41 
the whole period being taken as 100, and the 70 years being 
divided into seven decades, the proportion of the mean annual 
fall of each decade to the mean of the 70 years will be seen in 
the following table : — 
Decade. 
1813—22 
Proportional Eainfall. 
103 
1823—32 
101 
1833—42 
95 
1843—52 
98 
1853—62 
95 
1863—72 
100 
1873—82 
• • • 
• » • 
108 
It further appears that if the whole period of 70 years be 
divided into two periods of 35 years each, the mean annual 
rainfall of the first of these periods will be represented by 99, 
and that of the second by 101. 
Of the diagrams, it is only necessary to say that the first is 
a graphic representation of the last column in Table I., and the 
second a similar representation of the last column in Table III. 
