1841.] Woods Report on the River Indus. 567 



Current. miles, yards. 



The usual current in the freshes is, ... ..^ ... 5 992 



When the freshes are strong, 6 1272 



The greatest measured velocity, ... ... ... 8 323 



Between Attock and Kalabagh, where the river is hem- 

 med in by mountains, it is estimated in the freshes, ... 10 

 In the dry season usual, ... ... ... ... 2 1376 



Ditto ditto strong, ... 3 1248 



In a channel 1855 yards wide, the current in the middle of July has 

 been found to vary its strength in different depths as follows : — 



i fathom 2*7 knots. 



j do 3-4 do. 



1 do 4-7 do. 



11 do 2-9 do. 



2 do 4-8 do. 



21 do 5-8 do. 



By experiments with Massey's patent Log Machine, the ground current 

 of the Indus has been found equal in velocity to that of its surface. 



When the stream A encounters the bank at B, it is thrown off in the 

 direction C ; that part of the bed called D is thus cut off from a further 

 supply. An irregularity in the level is the immediate consequence, to 

 restore which, a surface stream rushes up, as represented by the coloured 

 arrow in the figure ; but as the water at the bottom of the surface 

 D runs off by the declivity of the river's bed, no equilibrium can take 

 place, while a rotatory motion, fatal to the bank, is given to a large 

 body of water in its immediate vicinity. 



