HATCHINQ FISHES' EGGS IN JAES 183 



above the other from the floor to the eaves of 

 the hatching-house, with a space of 5i/^ inches 

 between each. The exceptional trough is six 

 inches deep instead of twelve, is placed upon 

 or near the floor, and is used as a hospital. 

 The troughs are not set on a perfect level, but 

 with a slight slant so that the water will flow 

 better. The top trough slopes a trifle from the 

 inflow-tank or supplying pipe; the one beneath 

 slightly towards it, and so on to the bottom or 

 hospital trough. 



There are two outflows; one in the trough 

 immediately above the top of the fry-tanks, 

 which is placed at the end of the building 

 farthest from the supplying tank or pipe; the 

 other into the sewer from the hospital trough. 

 Arms or brackets, made of wood and shaped 

 like a flat dumb-bell with very long handles, are 

 fastened at regular intervals across the top of 

 each trough excepting the uppermost one. On 

 these brackets the jars are set on each side of 

 the battery. The water is flowed into the jars 

 by means of faucets and tubes from the trough 

 above ; and from them by means of the outflow- 

 lip into the trough against which they are set. 



