124 FARM BUILDINGS IN SOUTH AFRICA 



durable in the ground. It is used in waggon-making and for 

 disselbooms, long-waggons, swingle-bars, beams, etc. Iron 

 wood is very heavy and will not float in water. Beams as 

 large as 20" by 36" by 12 feet long can usually be obtained 

 without difficulty. 



4. Pteroxylon utile, or " sneeze-wood," is a small tree with very 



hard timber, which is almost imperishable in the ground, 

 and hence is highly prized for fencing posts. It has the 

 disadvantages of being irregular in growth (crooked, twisted, 

 etc.), and difficult to work. Large logs can be obtained. 

 The name comes from the tendency to sneeze induced in 

 persons working the wood, owing to its dust and peculiar odour. 



5. Callitris arborea, or " Clanwilliam cedar," is the most generally 



useful of all the indigenous timbers. It is as easy to work 

 as Baltic deal, seasons well, is very durable, and has a lasting 

 fragrance. This tree thrives only in its native home in 

 the Cedarberg country, about 120 miles north of Cape Town. 



6. Curtisia faginea, the timber of which is called "assegai wood," 



is a medium-sized tree. Assegai wood is prized for waggon- 

 making, spokes for wheels, etc. 



7. Apodytes dimidiata, or " white pear," is a medium-sized tree, 



the timber of which is used in waggon- making, and for 

 felloes, etc. 



8. Olea verrucosa, or " wild olive," furnishes good fencing posts. 



Decay of Timber 



Timber is least affected by decay when it is kept dry, and in a well 

 ventilated atmosphere. Some varieties, when kept completely and 

 continuously submerged in water, last almost indefinitely. 



Conditions which induce decay in timber are the presence of sap, 

 lack of efficient ventilation, and exposure to alternating wetness and 

 dryness. 



Wet Rot. — The common rot, affecting timber which is alternately 

 wet and dry, is called " wet rot." Wet rot affects only the surrounding 

 timber actually in contact with it, and if the bad part be cut away the 

 remainder of the wood will be found to be quite sound. Wet rot, unlike 

 " dry rot," is not malignant. 



