44 



FARM BUILDINGS IN SOUTH AFRICA 



The arch shown in Fig. 38 for an inside door requires no centering, 

 being built on top of the core (not shown) which, in turn, is carried by 



/' 



Fig. 38. 



the two 4t\" by 3" wooden lintels. This arch is intended to relieve the 

 lintels of some of the stress, and is therefore called a relieving arch. 



An arch over a fire-place is generally supported by an iron bar (or 

 bars) curved to fit the soffit of the arch, and called a turning bar. See 



Figs. 39, 46, and 47. Turning bars 

 may be made of old tyre iron. A 

 turning bar should have a bear- 

 ing on each jamb of 4£ inches, 

 and its ends should be turned 

 up, or down, for about 3 inches, so as to enter the vertical joints 

 between the bricks. A turning bar (or bars) serves as a centering on 

 which to build the arch, as well as strengthening it when built. The 



