THE FARM HOLDING. 



II-, 



Boulders and Floating Rocks. 



These are frequently found on good farm land, and are a source of 

 constant trouble, necessitating ploughing round them and often causing 

 breakages to machines. With the aid of explosives they can be removed 

 without the tedious work of drilling holes in them, by means of what is' 

 termed " plaster " charges. The number of plugs of gelignite in these 

 plaster charges varies from, say, five to twenty, according to the size of the 

 rock that is being handled. Very large rocks are better handled by drilling 

 a hole in them, as only a fraction of the explosive is then necessary to break 

 them up. In fixing these charges, one plug, with detonator and sufficient 

 fuse attached, is placed on the rock surface, and the other plugs of the charge 

 are placed all round and over it. The whole *is kept in position by an inch 

 thick covering of stiff plastic clay, well pressed down on to the stone round 

 the edges. The plaster, in addition to keeping the charge in position, serves 

 to exclude the air. Very little material is thrown about by this explosion, 

 but the report is particularly sharp and severe as it is in the open air. 



■ It is necessary to use a little thought in placing these charges, as the angle 

 of fracture, which varies in different types of rock, plays an important part 

 in the success or failure of the work. 



When handling " floaters " partially embedded in the earth, it is better 

 to clear the soil away from under them and particularly from dir ectly below 

 the spot where the charge is placed, so as to leave a hollow below, thereby 

 increasing the shattering effect of the explosion. 



It must be remembered that only a fraction of the gelignite used in these- 

 plaster charges would be needed if a hole was drilled in the rock, but it i& 

 not everybody that can successfully use a hammer and drill in rock, especially 

 when that rock happens to be granite. The plaster charge is, therefore,, 

 suggested as avoiding the tedious work of drilling at the expense of a little 

 extra gelignite. 



Post-hole Sinking. 



Although gelignite will render the ground soft and workable for the digging- 

 out of post-holes, it is questionable whether it is to be recommended as a 

 general practice, as the subsequent firming and ramming is rendered very 

 troublesome, and after a good fall of rain, posts so fixed are apt to be drawn 

 crooked by the strain put on the wires, due to the loosening up of the ground 

 for several feet around. Hard ground may be troublesome to work, but it . 

 is just this hardness that makes for permanent efficiency in fencing. 



Storage of Explosives on the Farm. 



Regulations as to the handling of explosives have been issued under the 

 Explosives Act, 1905, and persons acting contrary to these render themselves 

 liable to heavy penalties. 



Any person is entitled to keep explosives, such as gelignite, cheddite, &c, 

 together with detonators, up to a total weight of 25 lb. For any quantity in 

 excess of this amount, a magazine is necessary. 



Information concerning magazines and licenses for them may be obtained, 

 from the local police and from the Explosives Department, Sydney. 



