186 FISH CULTURE 



by the addition of a simple device in the shape 

 of a trough of tin or zinc, about the width of a 

 rainwater gutter, set in the trough at one side 

 and connecting the ends, two species can be 

 handled at one battery simultaneously and the 

 fry kept separate. By this means the water 

 from all the jars on one side of the battery 

 above the fry-tanks flows into the gutter in- 

 stead of into the trough itself. The tin trough 

 will also be found very convenient when two 

 or more fishes spawn at the same time. It 

 would be advisable when building the battery 

 to provide for the possible contingency of hatch- 

 ing two species of fish at the same time, by 

 dividing each trough lengthwise by a partition, 

 giving each an outflow-lip. 



Suitable Buildings. A building 60 feet long 

 and 32 feet wide, will furnish room for three 

 batteries with an aggregate capacity of 1050 

 jars, and six fry-tanks. Occasionally there 

 may yet be found a hatching-house for jar-work 

 in which the table system, with closed McDon- 

 ald jars, is still in vogue for temporary serv- 

 ices, but this method of hatching fish is rapidly 

 passing away. The battery marks as great an 



