PREFACE. Vii 



teem in every pool of water and running brook, 

 if this science I point to were brought out as 

 it should be. I believe water neglected, ill- 

 used water if properly applied, to be much 

 more valuable than land, through its greater 

 productive powers ; l and where the best species 

 of fish, as salmon and trout, can be cultivated, 

 capable of yielding a revenue very far exceeding 

 that of land. 



Water requires few or none of those expenses 

 demanded on land. Left to itself, it produces 

 and reproduces to a degree which, computing 

 by acreage, very far transcends the land. What 

 would our rivers and streams be worth if brought 

 back only to a state of nature, if man had 

 not (instead of cultivating them) almost de- 

 stroyed them ? But ought we to be satisfied 

 to restore our streams to their natural state, and 

 content to leave them so ? Is water-culture so 



1 What edible animal is there that exists on land, which possesses 

 the capability of reproducing 9,000 of its own size in a period 

 little exceeding eighteen months? This can, however, be per- 

 formed by a grilse of eight or nine pounds' weight. A grilse of this 

 size will deposit, say, 9, 000 ova in about fifteen or sixteen months ; 

 the fry from this ova go down to the sea, and in two or three 

 months more they have been known to come back to the river as 

 grilse of from five to ten pounds' weight. 



