476 Journal of the Asiatic Society of Bengal. [September, 1908. 
tary of the Ganges, has become a feeder of the Brahmaputra, aud 
tude and 90°, is therefore liable to vary between the 
plain of the Ganges and its peeves and that of the Brahmaputra 
- and its tributaries, the main agen ich causes a variation being 
a high flood. Diagram No, 2 sTlagtenten the conflict which has 
raged bececes these two great rivers in the last 150 years. We 
unprecedented flood of the Tista, robbed the Ganges of the water of 
the Tista River, ‘This piracy is ZeCy probably not the first of 
_which the Tista has been the victim; it has, in a A actgeraagela in 
bygone days, alternated, at different periods, b he 
master streams. Be this as it may, it seems & % not taliely 
ut the Brahmaputra has now finally become possessed of the 
ow the Kosi (old and new) Kis operated at different 
postin over adh the land between the debateable area along the 
junction of the Ganges and the Brahmaputra plains, and, roughly, 
Longitude 87° East; West of that Longitude and north of Latitude 
6°,the land is tolerably high, but south of Latitude 26° there is 
an area some 30 miles wide, which is lowlying; in this low-lying 
area minor channels of the main Kosi are at present busy 
building up most of the depressions. 
e sphere of action of the Kosi, then, since the Tista, Attri, 
and pt rivers, before the Tista last returned to the Brah maputra, 
apparently filled up fairly solidly everything east of Longitude 
8°, may be defined roughly as a rectangle made by the intersections 
of Longitudes 87° and 88° and Latitudes 25° 20”, and 26° 
respectively; of this area all, except on each side of Longitude 
87", appears to have been dealt with by the Kosi in its older ‘stages 
or bysmaller streams the hills north of Purnea ; the Kosi, 
therefore, is not likely to move appreciably either east or west of its 
present position. Inthe last 15U years the river has shifted slightly 
to the west, and its final point of entry into the Ganges may, I 
think, be safely put at less than 10 miles further west than the 
present Kosi bridge, the aroha being that the move will be much 
smaller, but the final exit will not be known _ the Himalayas 
are worn down to the posal ae level of the plains. Changes 
must be expected, but great changes only if the river is trained by 
s embankments which prevent it temporarily from carrying 
ppoval the work upon which it is engaged, which work it will 
- ly, in spite of any effort of man, eventually perform. 


