(3 
21. The position of the rain gauges from which the records 
at my disposal have been compiled, is badly selected for the 
determination of the phenomena of this nature, and there is 
reason to believe that the observations contained in the tables 
show b.ut imperfectly the real extent of change which has taken 
place in the more remote districts. And, as the presence of 
forests considerably modifies the distribution of rainfall and 
economises the water supply after it has fallen, and as agri- 
culture is principally dependent on these conditions, the pre- 
sence of a certain amount of forests in a country is not only 
necessary, but of the first importance for this, and those 
climatic considerations which naturally follow. 
25. Turning now to the tables in which are recorded the 
total Rainfall and number of rainy days throughout the year, and 
dividing the twelve years, over which the observations [extend, 
into periods of four years each for the sake of comparison, 
by setting off the total Rainfall and number of days on which 
rain fell against each period, any change which may have taken 
place since the first, period will become apparent; and, if 
apparent, it will be difficult to find any cause to which it can be 
ascribed other than to some local disturbance, or influence, 
which has been at work ; and equally difficult to find any such 
disturbing agent except that which has been effected by man 
in the removal of the natural covering of the surface of the 
island, which is kftown to have taken. place within the period in 
question, viz. 
Third period 
Total Rainfall. 
3 -s 
O ™ 
cc rri e3 
51 o 
© u £ 
H H S' 
jJ g 
■i'fed 
P C-I 
sS- 
Number of days on 
■which rain fell at 
Criminal Prison. 
• 
Inches. 
Days. 
Days. 
• 
398,62 
901 
787 
356.52 
829 
689 
42.10 
72 
98 
Decrease over first period. 
369.32 
820 
624 
• 
9 
65 
Continued decrease over 
second period. 
29.30 
81 
163 
Total decrease over first 
period. 
26. The above records [shew a steady decrease in the 
number of rainy or showery days, and what is further remark- 
able, is that, although the Rainfall of the last period shows a 
slight increase (12*80) over the second, the number of rainy 
