630 
Proceedings of Royal Society of Edinburgh. [sess. 
Remarks on the Rainfall Records in the Talla Drainage 
Area during the years 1896 to 1902. By P. D. Donald, 
A.M.Inst.C.E. Communicated by W. A. Tait, M.Inst.C.E. 
(MS. received February 10, 1905. Read May 1, 1905.) 
i 
A striking feature of the results obtained at the seven gauges in the 
drainage area is the divergence from the commonly accepted rela- 
tion between rainfall and height above sea-level. The following 
table shows the “theoretical” amounts of rainfall, averaging 62-51 
inches, that might have been expected at the several gauges, on 
the assumption that there was a uniform increase of 3 per cent, for 
every 100 feet of rise ; and in comparison with these, the amounts 
actually recorded, also averaging 62 '51 inches. 
Comparison of Actual Rainfall Records with Rainfall 
INCREASING UNIFORMLY 3 PER CENT. FOR EVERY 100 FEET OF RISE. 
G-aiige 
No. 
Height 
above 
Sea-Level. | 
“ Theoretical ” 
Annual 
Rainfall 
Average 
Annual 
Rainfall 
recorded. 
Difference 
in Inches. 
Percentage 
Divergence 
from “Theo- 
retical ” 
Rainfall. 
feet. 
inches. 
inches. 
+ 
+ 
1 . 
1496-05 
59-40 
56-22 j 
3-18 
5-4 
2. 
2627*34 
76-30 
65-53 
10'77 
14*1 
3. 
2258*28 
70-90 
66-02 
4-88 
6-9 
4. 
1859*92 
64-80 
66-82 
2-02 
3-1 
5a. 
1537-59 
60-00 
73-92 
13-92 
23-2 
6a. 
966-03 
51-30 
61-43 
10-13 
19-8 
7a. 
1196-48 
54-90 
47-66 
7-24 
13-2 
Average 
62-51 
1 62-51 
