Chapt. xii. Ascending by backwater. 147 



fish with an ill-regulated appetite. But a fellow worth 

 catching, such as I shall tell of shortly — never! 



"For you must take the current when it serves, 

 "Or lose your ventures." 



But why is it, you want to know, that the big fish in 

 estuaries cannot be content to feed in one place, like the 

 big fish in the rivers above tidal influence? Why is it 

 that they must be for ever advancing with the advancing 

 tide? You want a reason and I will give you one. If you 

 place yourself on a projecting rock, or stone-jetty, and 

 watch the first flow of the incoming tide, you will see in- 

 numerable shoals of minute fish from an inch long, and 

 upwards, coasting busily up the river.* They are near 

 the surface, and you can see them well. Keep motionless, 

 and as much out of sight as you can, that you may not 

 frighten them or any thing else, but may see them pursu- 

 ing their natural course. How pretty and sociable they 

 look. Dash into them goes a huge open-mouthed ruthless 



*They coast, because there is always a back-draught, or back-flow of 

 water, at the edge of every stream, in the opposite direction to the main 

 current of the stream, and caused by the stream carrying down by fric- 

 tion water that must return to fill up the vacuum it left, as soon as it is 

 released from the power of the friction that removed it. This backwater, 

 (not to be confounded with the common Indian name for an estuary) is 

 constant in all rivers throughout their length, and the tide on entering 

 a river, and while still contending with the current of the stream, takes 

 first advantage of this backwater, and accelerates it, till merged in the 

 general inflow of the tide. Small fish wishing to ascend a river take 

 advantage of this backwater, which is always running up each shore, 

 and thus by coasting they get up a river, without having to swim against 

 the stream. 



19* 



