CATTLE DIPPING TANKS 



239 



2£ inches of concrete, so as to make up the thickness of the bottom to 

 5£ inches (the remaining £ inch is applied later in the form of plaster). 

 Proceed in this way until the whole bottom has been laid. 



We next set the moulds or forms for the walls in place. A suggested 

 method is shown in Fig. 187. 



The studs or posts, of 3" by 3" deal, are set 3 feet apart centre 

 to centre, and are held in place at their upper ends by 2" by 3" cross- 

 pieces bolted to them and also to pegs driven into the ground. The 



Fig. 187. 



bolts which are later on to be used for the fencing of the race may 

 be utilised for this purpose, wooden washers being used if they are 

 too long. The studs are held apart by horizontal pieces of 2" by 3" 

 deal, called struts. The moulding surface itself is supplied by four 

 flooring boards held together by cross-bars (also of flooring boards) 

 9crewed to them halfway between each adjacent pair of studs. 



The forms are placed so as to mould the walls to a thickness of 

 5j inches. As the work proceeds, the four flooring boards are raised 



