70 PRACTICAL CARP CULTURE. 



into it. In either of the former cases the only hope is in the introduction 

 of cold water. 



The preventative of such a catastrophe lies in making the pond 

 deeper in all its parts. This can be easiest accomplished by excavating 

 the shallow places and placing the material taken out, on the dam and 

 embankments, making every scraperful count double in the water hold- 

 ing capacity of the pond. 



Where the pond is so situated as to make it practicable, the over- 

 flow of a cattle trough, supplied by a windmill, conducted in pipes to the 

 pond, will supplement the rainfall and reinforce the pond against the 

 work of absorption and evaporation, which agregates every 24 hours 

 about 6,000 gals, to every acre. 



WINTER DIFFICULTIES 



Consist chiefly in the death of fish under the ice. In our opinion two 

 causes contribute to this effect : Shallow water and poisonous gases. 



THE DEPTH OF WATER. 



This must be governed by the latitude in which the pond is located: 

 the climate having much to do with the depth of water required. In 

 Texas the deep water is needed in the hot season, that the fish may have 

 cool water to retreat too. In Minnesota they need deep water in winter 

 to have a warm place to retreat too. We have received accounts of carp 

 wintering successfully in water 3 feet deep and the ice from 20 to 24 

 inches thick, leaving only 12 to 16 inches of water. Now this is evidence 

 only of the hardihood of the carp and not of the skill of the culturist ; and 

 the carp are not the better for such a wintering. In a climate where ice 

 forms from 20 to 24 inches thick, the wintering part of the pond, the col- 

 lector and ditches, should not be less than 8 feet deep ; in warm climates, 

 4 to 6 feet deep. To winter carp well, keep them as warm as possible. 



POISONOUS GASES. 



Enough has been said and written on the subject of keeping air holes 

 in the ice for carp during the winter, to fill several books and to confuse 

 the authors themselves, let alone their readers. It has been argued that 

 these holes were neccessary for the introduction of oxygen into the 

 pond. Where it is cold enough to form ice on ponds that lasts any con- 

 siderable length of time, the carp will need but very little oxygen, and to 

 cut holes in the ice for this purpose is the heighth of folly. 



The decomposition of vegetable matter, animal matter, the food 

 unconsumed by the carp, all generate gases that are poisonous. These 

 gases will be found most plentiful in new ponds, formed by embank- 

 ments, not by excavation. Such ponds are usually formed with swales, 

 or morasses for their bottoms, and these bottoms contain a mass of 

 vegetable matter that has been for years in gathering, and as it decom- 

 poses gives off these gases. The gases arising from either of the above 

 sources, are injurious to the fish, and if they are long subjected to them, 

 results in asphyxia and death. The holes cut in the ice are to allow the 



