[21] 



POND CULTURE. 



487 



rest of the dike is finished. This is not advisable, however, in spite of its 

 requiring- one-tenth less shovelers for carrying the earth farther, because 

 it is much more laborious, and the seeming saving of labor is lost cither 

 entirely or in part, and because the portion of the dike thus interpo- 

 lated, as it were, will never join as firmly with the neighboring portions 

 as when it is constructed simultaneously with 'them, although it shoul<l 

 be particularly solid. For the sake of completeness, however^ we will also 

 make the calculation for this case. (2) In such a manner that the earth 

 is carried away on a line running at a right angle with the line of dig- 

 ging. This cannot be avoided if the portion of the dike bordering the 

 fish-pit is be constructed simultaneously with the rest of the dike, as on 

 the shortest straight line the laborers would hinder each other in throw- 

 ing the earth, as will appear from the drawing given below. (3) The 

 interference of the laborers with each other, mentioned under 2, may be 

 avoided by letting the men who have to remove the earth describe a 

 curve instead of a right angle on their way from the ditch to the dike, 

 which, moreover, has the advantage of causing a saving in shovelers, 

 wheelbarrows, and carts. 



It will be impossible, however, to lay down a general rule as to which of 

 these first two methods should be followed, because the configuration of 

 the ground will determine this in each case. Wherever practicable the 

 curve is to be preferred to the straight lines running at right angles. 



1. In the following figure the line A B G represents the edge of 

 the sole of the dike on the land side, and the line B D the proposed 

 mam ditch, and it is assumed that the cubic contents of one division of 

 the ditch corresponds to the cubic contents of earth of an equal division 

 of the dike. Supposing this to be the case we can assign to each squad 



