102 FISH CULTUEE 



r A number of years ago the Pennsylvania Fish Com- 

 mission had over 300 rainbow and brown trout killed 

 in its ponds in Allentown during a single thunder- 

 storm. At no time did the lightning strike nearer 

 than a quarter of a mile from the ponds. A former 

 manager of the Penn Forest Brook Trout Company, 

 a commercial establishment near Mauch Chunk, Pa., 

 informed me that during a severe thunderstorm more 

 than 400 pounds of trout were killed by lightning. 

 As long as the trout are swimming free in the water 

 no harm to them will result, but if any fish happens 

 to be on the bottom touching larger stones, and light- 

 ning should strike the ground anywhere within a 

 quarter of a mile or so, the fish would either be 

 stunned or killed. The true trouts are more liable 

 to injury from lightning than the brook-trout, because 

 the former are more likely to rest on the bottom. 



Size and Depth. The size and depth of tlie 

 ponds remain to be considered. These factors 

 must depend mainly on the water-supply, and 

 upon the purposes for which each pond is in- 

 tended. I prefer ponds of moderate size, and 

 believe for mature fish the deeper they are the 

 better, so long as they are not too deep for 

 handling. Those for advanced fry and finger- 

 lings should be shallower. An ideal pond for 

 advanced fry might be, say, 25 feet long, about 



