182 FISH CULTURE 



the operator to see that a full supply of water is in 

 the battery and carrying the fry, when they are 

 hatched, to the fry-tanks on the floor. Screens are 

 set in the cross tanks so that the fry must take a 

 definite route to the fry tanks. The hatching- jars 

 are fed from the troughs set lengthwise which are 

 fitted with ball-cocks to regulate automatically the 

 water-supply in the tubes and pipes. A battery of 

 this type is very expensive to build, requires much 

 water to operate it, and is now rarely seen. 



The second style of jar-battery is commonly 

 called the Alpena pattern, on account of its hav- 

 ing been built first in the United States Fish- 

 Hatchery at Alpena, Mich. 



The Alpena battery is so simple in design 

 that any intelligent carpenter can build one, 

 and is also thoroughly efficient and by no means 

 costly. An Alpena battery, with a capacity of 

 350 jars can be built easily for $150. Its only 

 weak point is that the egg-shells and fry are 

 carried to the fry-tanks through the troughs 

 which supply the jars with water, and may 

 sometimes clog the faucets. 



An Alpena battery is simply a number of 

 troughs, all but one being 14 inches wide, 12 

 inches deep and as long as desired, set one 



