When blasting out stumps of the semi-tap or lateral root variety, 

 that is stumps having both tap and lateral roots, the paramount idea is 

 to remove not only the part of it that projects above the ground, but to 

 cut off and displace the roots below plow level. It is therefore necessary 

 to place the charge well down in a central position below the stump in 

 order that the explosion may exercise an equal pressure on all the roots. 



A good many beginners in trying to carry out this principle make 

 the common mistake of calculating to get the bottom of the borehole 

 under the center of the stump as we endeavor to show in Fig. 121. As 

 may be observed that point would be the ideal location for the charge, 

 but it must be taken into consideration that if a charge of 3 cartridges is 

 used in a l^-inch borehole, this will occupy at least 20 inches of the 

 length of same, thereby leaving very little space for thorough tamping. 



Furthermore, the bulk of the charge would not be under the center 

 of the stump and would have the tendency to blow out the loaded side 

 only and in doing so it would probably remove only half of the stump, 

 leaving the other half remaining in the ground, with practically no soil 

 resistance to enable the blaster to put a fresh charge on the opposite 

 side. 



It is therefore apparent that an effort should be made to locate the 

 centre of the charge at a point beyond the centre line of the stump, as 

 shown in Fig. 122. To accomplish this correctly, a 1 ^2-inch diameter hole 

 should be bored at an angle of about 45 degrees inclined towards the 

 center of the stump. This hole should be started at a distance away from 

 the center of the stump equal to its diameter, and should be of sufficient 

 length so that the bottom of same will be past the center line of the stump. 

 PrimeXshould be made with cap and fuse. The instruction for making 

 the primer as also regarding loading and tamping should be carefully 

 carried out as contained on pages 119 to 124. 



Stumps having a large diameter can also be blasted out by the cap 

 and fuse method with a single charge by boring a hole past the center 

 line and enlarging end of same with one-quarter of a cartridge of dyna- 

 mite primed with cap and fuse. This small charge should be pressed 

 down to the bottom of borehole and should not be tamped. The result 

 will be as shown in Fig. 123. Under no consideration should the hol-e be 

 charged until it has had time to cool off. The best plan is to work on 

 other stumps awhile to give the chamber ample time to cool. 



"We recommend, however, that large stumps be blasted electrically. 

 This is done by boring auger holes either partly through or under the 

 principal spreading roots and one deep hole placed under the center of 

 stump (Fig. 124). All charges should be primed with No. 6 Victor 

 Electric Fuzes, wires of which should be connected together to form a 

 circuit. The first and last wires remaining should be attached to the 

 two leading wires which are connected to blasting machine. Although 

 large stumps can be successfully blasted by the ordinary cap and fuse 

 method, we recommend the electrical system, as there is an economy in 

 dynamite and results more satisfactory. 



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