36 FARM BUILDINGS IN SOUTH AFRICA 



are used. In Fig. 31 three different types are illustrated. The two 

 ties on the left are made of wrought iron, about 1|" by J" in cross 

 section. The ends of these ties are split, and splayed out, so as to give 

 them a good hold in the mortar. One of the ties shown is twisted, while 

 the other is bent down, at mid-length, in order to throw off any moisture 

 coming from the outer portion before it reaches the inner portion of the 



Fig. 31. 



wall. The third tie illustrated (on the right) consists simply of a piece 

 of wire — several strands twisted together — bent so as to gain a grip in 

 the mortar. Such ties may conveniently be made from twisted wire 

 droppers for fences. All the above ties should be dipped, while hot, 

 in tar, before being built into the wall. 



An objection to wrought-iron ties is that they are subject to rust, 

 which may cause them to expand, and so injure the wall. 



