1895.] 
F. A. Shillingford —On the Kusi River. 
13 
the ocean by the shortest route, and then each affluent from the northern 
mountains would tend to deflect her course farther and farther to 
the south. In this position the usual detrital accumulations would go 
on lifting the river above the surrounding country, until the ever in¬ 
creasing force of the current of overflow of its spill-waters, due to its 
constant elevation, would ultimately break—during heavy rain or un¬ 
usually high freshets—a new channel for the river into the lower coun¬ 
try which would naturally be in a direction away from the mountains 
whose own detrital slopes are ever on the increase. This new channel 
would undergo the same filling up process, and when the next shift took 
place the raised banks of the channel just previously deserted, would 
form a sort of barrier against the immediate return of the river in that 
direction, and a farther deflection away from the mountains would take 
place, and this “ constant westerly movement ” would go on until the 
limit was reached and further westward movement checked by the 
general slope seaward of the great Gfangetic Plain. The Kusi has 
never been known to return eastwards to any of its deserted channels, 
but has been steadily advancing westward, the successive leaps forming 
as it were a series of terraces with the slope facing East. Denudations 
and the products of denudation have tended towards levelling off the 
former “ ridges ” along which the main waters of the river were 
carried along. That the Kusi must again come eastwards will be 
apparent to any one who gives the matter a moment’s consideration. 
We know the Kusi has moved westward through a space of about 60 
miles, measured along the Ganges, since 1731, and that it cannot go up 
country much further. The summer level of the Ganges at Monghyr, 
to the North of which the Kusi flows at present, 
is 101'83 feet above mean sea level, whilst 
at Sahibganj opposite to which the Kusi of 
1731 discharged its waters the summer level of the surface of the 
Ganges is only 68 feet above mean sea level. It is apparent that this 
“ constant westerly movement ” is not taking place for the special 
benefit of our Government, but must have been repeated over and over 
again in past geological ages since the upheaval of the Himalayas and 
the gradual formation of the Indo-gangetic Plain, and when the eastward 
movement is again accomplished, it may be in the power of distant 
generations to repeat that the Kusi is remarkable for its “ constant 
westerly movement.” As to the time and manner of its going eastward 
again, it is difficult and hazardous to form an opinion. Fergusson, 
referring to the period when he considers the combined Kusi, Mahanan- 
da, and Atrai flowed through the Urasagar, says, 1 “ Were it possible, it 
1 Quar. Jour. Geo. Soc., page 245. 
Gradient of 
Ganges surface 
the 
