1918.] The Fifth Indian Science Congress. Ixxxiii 
the Dona Charhda assessment circle is related to the previous 
rainfall. Naturally if a peasant realizes that there has been 
rain enough to sow his wheat on unirrigated land he sows it 
there, and the area sown on well-irrigated land is diminished. 
The lowest curve gives the actual area compared with the area 
as deduced from the rainfall. 
e€ may now turn to America where the Agricultural 
Department have been most energetic and successful in work of 
this kind. As an example I have taken the Georgia cotton 
crop which is largely dependent on temperature in May and 
June. e diagram! shows how a forecast may be based on 
this. When the process of ginning is actually going on they 
are still anxious to know what the total crop will be: and the 
lower diagram illustrates how this may be obtained from the 
amount of cotton actually gained between the Ist September 
on es 14th November and the number of fair days in that 
interval. 
The topmost on the screen ® gives the proportion of those in 
land who when married cannot write and put a mark on 
18 a very intimate and reliable relation between illiteracy and 
‘ mployme 
uingly iving you as the fourth curve on the screen the 
‘uctuations in the marriage rate, and as the third the fluctua- 
ons in the sum of exports and imports per head. It is now 
quite clear that the prosperity of the country is the dominat- 
m8 factor. When trade is good unemployment is small: at 
SS Lean eerie dake aide se dc 8 
' See F’g. VI. 2 See Fig. VII 
