i6o 
CLEARING WITH EXPLOSIVES. 
The Value of Explosives in Clearing. 
It will be found that the chief uses to which explosives can be. 
put with economy in clearing land, are in the removal of stumps, 
and in so shattering logs or standing trees that they burn more 
readily. Trees can be blown right out of the ground; but, owing 
to their greater weight they take more explosive than stumps. 
I therefore consider it more economical to put sufficient explosive 
under them to blow the earth out from around the roots, at the same 
time cracking and breaking the roots and butt of the tree. The 
cracks will extend from 4 to 15 feet up the trunk of the tree; and 
after a week’s exposure to the air in dry weather, even bad burning 
timber will then burn readily. I have burnt down trees 7 feet in. 
diameter at the ground in six to twenty four hours having used $$. 
worth of explosive on some. These trees would have taken a week 
to burn down in the ordinary way, that is, digging the earth away 
from them, and drawing timber around them with horses or bullocks. 
The economy of the method will be realised when I state that 
I have cleared 12 acres of land at a cost of £3 per acre, whereas 
an adjoining block of similar land cost me about £6 per acre to clear 
in the old way. This was on light red volcanic soil, overlying light 
clayey loam. 
The method cannot be recommended in cases where timber burns 
right out of the ground, leaving no roots. But in this district 1 have 
found the saving in cost to vary from 25 to 50 per cent, on the usual 
methods of grubbing and burning. With practice, much better work 
can be done at less cost with explosives. The procedure should be 
varied to suit different timbers and different soils; the exercise of 
a little judgement will be found profitable. 
Sound timber, whether trees, stumps, or logs, will be shattered 
with better effect than hollow or rotten timber, as it offers more 
resistance to the explosives. 
Condition of the Soil. 
To obtain best results I find that the ground requires to be fairly 
dry. If it is very dry, the explosion is not quite so effective; whilst if 
it is too wet, the force seems to act too deeply in the earth, instead of 
near and above the surface. In some districts, I am informed, best 
results are obtained when the ground is wet ; but that is not my ex- 
perience and I do not know to what degree it holds good. 
Explosives Recommended. 
For firing, a battery guaranteed to fire five or more shots is 
absolutely necessary' for best results. It is possible to work in small 
timber' with fu'se and Caps,' but the method is not so satisfactory as 
the use of c battery. ' 
