92 THE EQUIPMENT OF THE FARM. 



inches below the level of the pond, and filled in with con- 

 crete. If a facing of brick or stone be thought desirable, 

 it should not be less than nine inches thick, flushed in with 

 cement or hydraulic mortar. We have successfully used 

 concrete for this purpose : a rough framework is used to 

 keep the concrete in a vertical position until it becomes 

 solidified. At distances of three feet apart on the bottom 

 level a dovetailed recess is cut in the face of the bank, and 

 filled in with concrete ; as the work proceeds these form 

 "buttresses which secure the wall in an upright position. 

 When finished the top should be protected by a covering 

 of soil, and securely fenced on three sides. Shade is ot 

 some importance, as it retards evaporation ; at the same 

 time, it is a mistake to plant trees too close to the pond. 

 When full grown and clothed with foliage, they form a 

 powerful leverage on which the wind acts, causing the 

 hanks to slip and crumble away. 



In clay districts a less costly drinking pond is made by 

 merely fashioning out the cavity, of the requisite dimen- 

 sions and depth, in the hardened subsoil ; thereafter laying 

 6 inches of puddled clay upon it ; then flagging roughly 

 with any flat stones, jointing these with mortar containing 

 cement; afterwards causewaying it with stones on edge from 

 6 to 8 inches deep. This makes a very permanent job and 

 when made four-square at the corner junction of 4 fields 

 the angles should be in the lines of the fence, and these 

 continued into the midst of the pond, which thus provides 

 .a water supply to four fields. The drainage of the field 

 may be conducted into the pond ; and provision for 

 carrying off the overflow should be made. 



