76 FISH CULTURE 



To these Mr. Cole adds a fourth type, namely 

 winter ponds, located in sheltered spots, which 

 should have a depth of six to eight feet. Winter 

 ponds are only necessary where the stock or 

 raising ponds are not suitable for carrying fish 

 from autumn to spring, that is to say, where 

 the water would freeze to or nearly to the 

 bottom. 



Generally, it is not wise to build any ponds 

 for the cultivation of carp by damming a stream 

 unless there is no possibility of a freshet. 

 Should it be found cheaper, and otherwise good 

 policy, to build in this manner, an artificial 

 ditch should be built the whole length of the 

 pond, at one side, to carry off surplus water. 

 If a dam built across a pond were to break out, 

 or an overflow to occur of any considerable 

 depth, an almost total loss of fish would result. 

 This is peculiarly the case with carp, for that 

 fish more than most follows currents and 

 changes in depths. If surrounding land be- 

 comes submerged, for instance, nearly every 

 carp will swim from the pond to the submerged 

 lands. 



The third type, described by Mr. Cole as the 



