Since, according to lleseck, impregnated nets are from 30 to 100 percent heavier than 

 non-impregnated nets, the nets which are mostly impregnated and purchased according to 

 weight are mostly too expensive. It is very simple to impregnate the nets one's self. 

 Tar, T^iich makes the nets stiff and Carbolineum which contains poisonous and ill-tasting 

 phenols, cannot be used in pond fisheries. Ikleseck recommends the plant extracts catechu, 

 quebracho, mangrove bark extract and gambler. For iinpregnation, the nets are cooked for 

 hours in a kettle having an inset to prevent burning. Even better is an impregnation at 

 about 60° C (in a kind of cooking box) for 21^ to W^ hours. According to Meseck, 1 kilo- 

 grajii of plant extract in about -iO liters of impregnation fluid is required for 10 kilo- 

 grams of net (10 pounds of net require 1 pound of extract in A. 3 gal. of fluid). The 

 cost of ijipregnation for 10 kilograms of net amounted to 1 to 2 marks {2U to ;48 cents) 

 in 1928, Starfish impregnation, which in later experiments of Ueseck showed by far the 

 least decrease of strength, is only done by the Worsted Yam Spinning Mill in Delmenhorst 

 on the factory scale. 



Length^"- ice coverage with beginning suffocation offers a welcome opportunity for 

 the thorough fishing out of non-drainable ponds. If holes are knocked into the ice, the 

 fish gasping for air, come swimming to the openings and can be easily caught. Electric- 

 ity has become a valuable aid for fishing out of dilficult fishable and non-drainable, 

 locked waters, thanks to a 1-rge series of experiments. The experiments have shown that 

 fish catching by electricity is thoroughly profitable, and injuries to the waters as 

 well as to the fishes do not occur. Alternating current of ^0 amperes and 220 volts or 

 70 amperes and 130 volts which can be taken from overland power lines, has an active 

 range of about 2 meters (6-| ft.) in water. The fishes, both large and small in the 

 same manner, when they get in this range, carry out circular movements or lie rigid at 

 the surface with stilted slightly trembling fins. The skin at the same time becomes 

 very pale. Even large carps which seem to be almost dead, revive completely in five 

 to ten minutes. A disadvantage is that the stunned fishes often rapidly sink again 

 into the depths and therefore must be rapidly caught by nets from the boat. For the 

 catching apparatus a U millimeter thick copper wire which is fastened to floats so that 

 it is suspended 10 centimeters below the water surface. The ends are provided with 

 porcelain insulators to vhich cords are attached for pulling the apparatus through the 

 pond. The wire itself is connected with the electric circuit. Great care is always 

 necessary. Details are contained in the fundamental thesis of F, Schiemenz and 

 Schoenfelder, and in the theses of Schumann and of F. Schiemenz (1932) who reports the 

 theses of Holzer, Explosions are unsuitable for the fishing out of non-drainable ponds, 

 even vriien these are very small (Potonie and Wundsch) , 



The point of time for the fishing out of ponds by draining, falls in October and 

 November in carp growing and maturing ponds, with early fishing already in September, 

 and with winter ponds in March, April and May. The necessity of fishing out the large 

 carp ponds only once in autumn, stamps the carp trade, even today, as a seasonal busi- 

 ness. The sale of trout, since it does not have this peculiarity, is distributed over 

 the entire year. With trout ponds the time point of fishing out is very variable. Fish 

 catches must always be made in cool weather, and early in the morning in sunnier, and 

 must never be done during frosty weather, PVeezing of the skin causes severe injuries 

 and leads after a short time to the death of the fishes. 



Every fishing out must be most carefully "prepared for in advance. The sheltering 

 of the fishes during and after the fishing out must be exactly regulated. Everyone who 

 helps with the fishing out must know in advance, exactly what he has to do: sorting, 

 weighing, loading or something else. The draining of the ponds takes place very 

 gradually so that all fishes go along with the drawn off water (see Fig. 19). With 

 small ponds it lasts several hours, with large ponds it lasts for days, even weeks. 

 Before a sluice board is pulled out, the water must first be confined by setting up 

 sluice boards in the diverted sluice channel in the pond. Then a sluice board can be 

 removed from the other channel and a restraining grid frame or the sieve box can put 

 in place (Fig. 10). It is still better to place the grid way down in the channel 

 turned toward the pond, and set up sluice boards on it to extend above the water sur- 

 face, and to pull one board after another from the diverted channel to regulate the out- 

 flow. Clogging of the sieve is thereby avoided and the pulling of another sluice board 

 is made considerably easier. Shortly before running empty, the sieve frame should be 



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