26) Scientific Proceedings, Royal Dublin Society. 
g y y 
and also the area on the map lying between 20° and 30° latitude, 
and within 10° longitude. 
The tracings were then carefully cut out and weighed, with 
the following results :— 
(1.) Rain-basin of Ganges above Ghazipur 
(weight of tracing) é = 0°2265 grm. 
(2.) Rain-basin of Ganges below Ghazipir 
(weight of tracing) .. = 02780 5, 
(3.) Rain-basin of Brahmapitra leat ght a 
tracing) ‘ ‘ = 0°4620 ,, 
(4.) Standard area taseighe BP easing) .=0°5150 ,, 
I ecaleulated the standard area at 325,660 sq. geo. miles.* 
From the above we readily find. 
Ganges. 
Rain-basin above Ghaziptr — 145,220 geo. miles. 
Rain-basin below Ghaziptr = 175,790 ,, = 
Total, . . 319,010 geo. miles. 
Brah maptitra. 
Total Rain-basin, , . , . 292,140 geo. miles. 
This result gives a total discharge for the Ganges somewhat more 
than Toile the Ghaziptr aaecanee (instead oF feur or five times), 
or, exactly— 
Annual Discharge = 97-170 cubie miles (statute). 
The dry season discharge of the Brahmapttra, at Gwalpara, 
near the head of its delta, is given by Major Wilcox,t as 150,000 
cubic feet of water per second ; and I have calculated (by reduc- 
ing Everest’s discharge of 36,330 cubic feet per second, of the 
Ganges, at Ghaziptr) the Gangetic dry-season discharge at a 
point corresponding with Gwalpara, on the Brahmapititra, toe 
amount to 76,000 cubic feet per second. — 
If we adopt this ratio, we find, for the ya 
Annual Water discharge of the 97- Bia 
Brahmapitra, re 
=191-78 cubic Sats (statute). 
* By integrating the expression 7? sin 0 d@ dd between the ears named, where 
r=radius of earth in geogr. miles=3958 x Gor OT’ 
north polar distance 
¢=longitude. 
} Asiatic Researches, vol. vii., p. 466. 
