246 FARM BUILDINGS IN SOUTH AFEICA 



inslide with as little handling as possible, a couple of sheep beiDg 

 placed in the pen to act as decoys. 



As originally built the tank was 5 feet in diameter at its widest part x 

 but this was found to be rather small, and in the accompanying plans the 

 maximum diameter is shown as 6 feet. Such a tank is large enough to 

 dip from four to six sheep simultaneously, according to size of breed. The 

 tank decreases in diameter towards the bottom, which has the effect of 

 keeping down the fluid capacity, and also the amount of building material 

 required. The tank, if built to the dimensions given, will contain approxi- 

 mately 505 gallons when filled to the lip of the inslide. In order to 

 deflect splashes back into the tank, it overhangs slightly inwards at 

 the top. The tank itself and the outslope walls are built of bricks laid 

 in ordinary blue hydraulic lime mortar, while the inside of the tank 

 and outslope is rendered (or plastered) with cement mortar. 



Building the Tank. — Those bricks forming the bottom of the tank 

 are laid on edge on a layer of lime mortar deposited on the bottom of 

 the hole which has been excavated to receive the brickwork. 



The bricks forming the walls, are built in heading bond, i.e. with their 

 longest dimension lying across the thickness of the wall, as shown in 



Fig. 191, which is a quarter plan of one course 

 of bricks. The broken lines show the position 

 of the vertical joints between the bricks com- 

 posing the next course. These joints lie 

 halfway between the joints of the first- 

 mentioned course. The bricks are laid in 

 this way so as to avoid continuous vertical 

 Fig. 191. joints. 



As a guide in the building, a wooden templet 

 is employed, revolving about a f-inch round iron rod, as shown in 

 Fig. 192, which gives a view of the templet on the right of the iron 

 rod, and a fully dimensioned outline of the templet on the left. The 

 iron rod is fixed vertically by building the lower end into the brick- 

 work forming the bottom of the tank, and passing the upper, end through 

 a hole in a wooden beam, supported at each end by a temporary 

 brickwork pier built in lime mortar. These piers might, if desired, 

 be displaced by wooden posts. 



For the sake of cheapness, bricks of a good red variety may be used. 

 In order to fortify them against the moisture in the surrounding earth, 



