76 TROUT FISHING 



For this reason, at the opening of the 

 season anglers seek their sport along the 

 northern shores. It is a true instinct that 

 guides them thither. At the opening of 

 the season trout are most frequent where 

 the water is least cold. Why, then, it 

 wiU be asked, does sport along the shore 

 sometimes fall off when spring has ad- 

 vanced a stage ? 



The answer will arise on consideration 

 of a characteristic in which water is in 

 harmony with all substances other than 

 explosives such as gunpowder and nitro- 

 glycerine and dynamite. Heat does not 

 act upon it so quickly as it acts upon 

 earth, or so slowly as it acts upon wood ; 

 but water is like all of the substances 

 which we meet in the fields or in the 

 woodlands in that its permeation by heat 

 or by cold is gradual. Small bodies of 

 water, which are more quickly heated than 

 large bodies, are also more quickly chilled. 

 By the middle of April the general body 

 of water in a lake is of a sensibly higher 

 temperature than it was in January; 



