190 



THE FARMERS HANDBOOK. 



mouth of the scoop wears ^ery thin, and will easily buckle. To counteract 

 this a piece of quarter-inch steel, « r > inches wide, is riveted across the mouth 

 and bevelled at the same angle as in Fig. 3 (b). 



Removal of the Earth. 



The ground should be carefully ploughed before scooping commences, par- 

 ticular attention being paid to the uniformity of depth, so that the scoop will 

 not bob up and down. The earth on which the embankment is to be built 

 should also be ploughed, so that the removed earth will incorporate with it 

 should the water overflow the excavation. If this is not done there is a 

 risk of the water percolating between the hard undisturbed soil and the loose 

 soil of the embankment, causing " weeping," and creating the possibility of a 

 breakaway. 



Fig 2. — Back of scoop showing cradles. 



A frequent error of judgment on the part of tank-sinkers is the practice of 

 placing the first scoop of earth near the margin of the excavation. This means 

 that the horse has to drag the next filled scoop over the bank so formed. It is 

 obvious that the operations should be reversed, and the earth placed at the 

 back first and the embankment built up from behind. To increase the storage 

 capacity the embankment should be built well forward. Usually the earth is 

 banked on two or three sides, but it is an advantage to bank it right round to 

 prevent evaporation as far as possible. 



