212 DOMESTICATED TROUT. 



the sides to facilitate moving. It must not be made 

 too large round, or it will not go into the door of the 



Conical Tank for the Transportation of Young Fry. 



express-car, which would be found to be a very seri- 

 ous difficulty. 



The best form that I have found for a tank for trav- 

 elling with live fish is the conical one given in the 

 accompanying plates. The advantage of the conical 

 shape is, that the water, on being agitated by the mo- 

 tion of the car or vehicle in which it is carried, aerates 

 itself by spurting up the sides of the cone and falling 

 back into the tank, in consequence of which the tank 

 becomes, when in transit, a self aerator. 



The tanks are sometimes made of wood and some- 

 times of tin. The measurement of three different sizes 

 used at the Cold Spring Trout Ponds are as follows : 



I. Height 48 inches. 



Diameter of bottom . . . . 29^ " 

 Diameter of opening . . . .17 " 

 Diameter of top . . . . 9 " . 



