[^yj POND CULTURE. 505 



water. The case wUl be different if the bottom of the pond has a hiyer 

 of good earth on the top, then sand below this good earth, and below 

 this sand good earth again. Neither wood nor stone dikes will then be 

 necessary, but a dike made partly of earth and partly of sand and 

 gravel, covered with one of the coverings described above, will answer 

 the purpose. 



D. — Fascine dikes. 



These dikes are made of fascines in the following manner: A layer 

 of fascines is placed along the entire breadth of the sole in the natural 

 soil, and fastened in the ground at intervals of 30 centimeters, with 

 sticks or pegs measuring 60 to 70 centimeters in length. The' next 

 layer of fascines is placed crosswise over the first, the next lengthwise, 

 the next again crosswise, and so on until the dike has reached a proper 

 height and shape. Great care should be taken that the seams of the 

 fascines are not one above the other. Every layer is anchored, like 

 the fascine covering, at intervals of 2 meters, and each individual fas- 

 cine is pinned to the one below with pegs measuring 1 meter in length 

 at intervals of 60 centimeters. Each layer is well filled with sand'^or 

 gravel before the next layer is put on. Such a dike should have a 

 gentle slope, and the walls, as well as the crest, should be covered with 

 good earth (if possible) to the depth of 25 centimeters and well rammed 

 down. If the outer fascines are made of willow branches there will 

 soon be a growth of young willow shoots. Fascine dikes are very dura- 

 ble, but they require an enormous quantity of branches, and if there 

 is a lack of binding earth, the covering will also have to be fascines or 

 wicker-work. 



No rules can be laid down as to the material for building the wall 

 and constructing the covering, as this will have to be determined in 

 each case by the local circumstances, especially by the degree of firm- 

 ness which the dike needs in proportion to the size of the pond and the 

 mass of water rushing against it; and, in the second place, by the 

 building material at one's disposal. In a work like the present we can 

 only point out the advantages of one method over the other, leaving to 

 the pond culturist the choice of the methods, according to his peculiar 

 circumstances; and it is not supposed that, in a case where wicker-work 

 answers all purposes, he will choose the more expensive fascine cover- 

 ing, even if he should possess all the necessary material therefor. 



2. THE MAIN DITCH. 



This ditch should cross the entire pond in a straight line from tbe 

 place where the water enters to its outflow. As it will be found advan- 

 tageous to have all ponds so constructed as to allow the wintering of fish, 

 the main ditch should, wherever the given quantity of water permits it, 

 be at least 1.5 meters deep. The width of the ditch at the top will be 

 determined by the base line of the slope ; if the slope is gentle, it will be 



