24O DOMESTICATED TROUT. 



when there is plenty of it and the season is not par- 

 ticularly dry. This point has also been discussed on 

 page 12, to which the reader is referred. I will re- 

 peat here that the extreme limit of danger is variable, 

 depending upon the quantity, quality, and rapidity of 

 the water, and also upon the degree of exposure to 

 the sun, and the condition of the fish. 



The trout exhibited by the writer at the Mechanics' 

 Fair, at Boston, in 1869, appeared easy with a medium 

 supply of water at 68°. At 70° they were a little dis- 

 tressed, at 73° much distressed, and breathing at the 

 rate of 100 times a minute. Mr. Stephen H. Ainsworth, 

 in a letter to the writer, says that 68° is the highest 

 temperature that his trout do well in, at 70 they stop 

 eating, at 75 begin to die, at 80° die faster, and at 

 90° all die. Seth Green's book says that trout will 

 die at 68°.* This may be the case in New York, but 

 it is not so in New England. Trout in our vigorous 

 swift running water will sometimes live through 75°. 

 Still I consider 75 very dangerous, and anything over 

 70 unsafe. 



There is no remedy for the water heating up, except 

 artificial cooling. If you have ice enough, you can do 

 something in that direction in a small stream as long 

 as the ice lasts ; but it is a forlorn hope. However, 

 if you find the water heating to a fatal extent, and 

 think it worth while to try to save them with ice, first 

 diminish their rations or stop them altogether, make 

 the current as swift as possible, and then do what you 

 can with ice. You will probably save some, if the 

 heated term does not last too long. But if your brook 



* Trout Culture, p. 52. 



