1904-5.] Rainfall Records in the Talla Drainage Area. 
631 
If the position and exposure of the gauges are taken into con- 
sideration in the comparison of the records, the result very strongly 
corroborates the conclusion that has been drawn from the results 
of similar gaugings elsewhere, that in high -lying districts the 
greatest rainfall is to he expected, not on the summits of 
the hills, hut in the valleys between. Gauges Nos. 5a and 6a, 
which have the highest records of rainfall, and show the greatest 
divergence from the 3 per cent, rule, both on the side of excess, 
are situated in valleys with steep sides, rising to 500 feet above 
the gauge level in the case of No. 5a, and 900 feet in the case of 
No. 6a. Gauges Nos. 2 and 3 are on the summits of the highest 
hills in the drainage area, and No. 7a, which, with the exception 
of one year, has, by a considerable amount, the lowest record of all 
the gauges, is situated on the summit of a ridge on the watershed. 
Dividing the gauges, therefore, into three groups, a comparison may 
be made of the records obtained at similarly situated gauges, as in 
the following table. 
Increase on Lowest 
Percentage 
Increase per 
100 feet of 
Rise. 
Gauge 
No. 
Height. 
Average 
Annual 
Gauge. 
Rainfall. 
Inches. Per cent 
A. Gauges near Watershed, but in Depression between 
Watershed Summits. 
1 . 
1496-05 
56-22 
4. 
1859*92 
66-82 
10-60 
1*8*9 
5-25 
B. Gauges on Watershed Summits. 
2. 
2627-34 
65*53 
17-87 
37-3 
2-6 
3. 
2258-28 
66-02 
18-36 
38-4 
3-6 
7a. 
1196-48 
47*66 
C. Gauges in Valley 
s at foot of steep slopes. 
1 
5a. 
1537-59 
73-92 
12'49 
20-4 
3*6 
6a. 
966*03 
61*43 
As may be seen in the table next following, the records at gauge 
No. 1 show almost twice as much total variation, in relation to the 
