148 THE NEW ART OF BKEEDING FISH. 



at F, having no communication with either of the 

 other ponds. The waste water from pond No. 1 is 

 conducted into pond No. 2 through a square wooden 

 pipe, covered at the mouth with a wire grating, the 

 bars of which are ahout one-eighth of an inch apart. 

 The waste water from pond No. 2 is conveyed under 

 ground, to the distance of 20 feet, in a square wood- 

 en pipe, grated in the same manner as the former. 

 The waste water from pond No. 3 passes down a 

 square wooden pipe, two feet deep, covered at the 

 top with wire-gauze, and is conveyed underground 

 in a small covered drain to the distance of 20 feet 

 from the pond. The water of the whole is then left 

 to find its way to the river. To prevent any com- 

 munication arising from an accidental overflow of 

 the ponds themselves, I raised embankments upon 

 the intersecting walks of two feet in height, so that 

 the several families of fish which the ponds contain 

 can have no access, direct or indirect, to each other. 

 Where the rivulet is divided for the purpose of sup- 

 plying the several ponds, I have formed an artificial 

 fall in each stream, of a construction to prevent the 

 fish from ascending one stream and descending an- 

 other. Finally, where the water discharges itself 

 from the ponds, the channels are so secured by wire- 

 grating that it is as impossible for the young fish 

 to escape as for any other fish to have access to 

 them. The whole occupies an area of nearly 80 

 feet square. My experimental basins being thus 

 prepared, my next object was to secure the fish, the 



