STOCKING 389 



down the stream from the sill against which the screen 

 in each case is to be fixed. If the ground is loose or 

 peaty the wings must be cut out further into the bank 

 and further down the stream. The wings must be 

 cut down to the hard gravel at the bottom of the stew 

 and the ground must be made level from side to side 

 along the line of the sill. The sill, which should be of 

 good, solid, well-matured English oak, 4 in. by 3 in., is 

 set on edge and firmly bedded in the gravel. Mr. 

 Corrie suggests that for a sill, which is at all times 

 under water, green elm or green beech (i.e. unseasoned 

 timber) will outlast the best matured oak. It must be 

 long enough to extend to the pile at the inner end of 

 the wings on each side. 



Close behind the sill at the place where the end of 

 the screen will come, drive an elm pile 6 inches square 

 on each side, marked A in Plate XXXIX, a similar 

 pile in a line with it at the inner end of the wing 

 marked B, and another similar pile at the lower end 

 of the wing marked D on each side. Another pile 

 marked C is driven immediately behind the sill in the 

 centre of the stew, and all these piles are cut off at 

 about 3 feet above the summer level of the water. 

 Nail the sill firmly to the piles marked A, B, and in 

 front of the sill lay 2 inches of concrete on the upper side 

 on the bed of the stew, thus leaving the face of the sill 

 against which the screen is fixed projecting 2 inches 

 pointing upstream. Where there is much fall of level 

 in rear of the screen the footing of the sill must be 

 made secure by driving a row of beech piles on the 



