6 4 



tamping rod. The plug of dynamite to which the detonator and 

 safety fuse are attached, called the primer cartridge, is put in 

 last. ' The length of fuse used should be sufficient to allow of 

 two or three inches projecting at the top of the hole. The hole 

 being thus loaded must then be filled in with earth or sand, which 

 is firmly pressed down with the tamping rod. All is now ready 

 for exploding the charge, which is done by applying a light to 

 the end of the fuse. A number of holes can be prepared and 

 loaded and fired together in quick succession, this being speedier 

 and more convenient than firing each one as soon as it is ready. 



The mode of procedure is explained at greater length in the 

 illustrated booklet. " Explosives for Subsoiling," which can be 

 obtained by farmers gratis from the Cape Explosives Works Ltd., 

 Somerset West. This also describes the necessary drilling out- 

 fit, which is simple and inexpensive. 



After blasting, the pot-hole formed by the explosion must 

 be properly filled in with earth, care being taken that no air space 

 is left at the bottom of the hole. To provide for subsidence of 

 the soil the tree should be planted in a mound above the level of 

 the ground. It is advisable to allow the soil to settle for a few 

 weeks at least before planting. Some farmers even advocate 

 planting the tree the season following the blasting of the holes. 



The best time to dynamite is when the ground is dry, the 

 object being to pulverise and crack the soil, not to cake it. Clay 

 subsoils should never be blasted when wet, as a pocket is then 

 caused in which stagnant water may collect with fatal results to 

 the tree roots. Although general experience, as would seem 

 natural, is in favour of planting trees right on the surface above 

 where the hole has been blasted, it may be mentioned that some 

 farmers prefer planting at one of the sides instead. This plan 

 was recommended in a paper read some time ago before the Mid- 

 land Farmers' Association by Mr. Murray, of Temple Farm, 

 Schoombie, who is an enthusiastic advocate of dynamiting, his 

 views being the result of practical experience in hard Karroo 

 conglomerate, in which it appears there is some risk of trees dis- 

 appearing if planted right on the seat of the blast before the soil 

 has had ample time to settle. 



For subsoiling existing orchards, dynamite can be used with 

 advantage, and excellent results have been obtained by applying 

 it to trees which were not flourishing or had begun to yield 

 poorer crops. The procedure in this case is to explode one or 

 two charges in holes seven or eight feet from the trunk of the 

 tree. Tt is advisable to treat growing trees during the dormant 

 season only. 



Dynamite subsoiling is cheaper than trenching, and for this 

 reason has been adopted in many vineyards with most successful 

 results. 



