Digging Post Holes 



Only enough dynamite should be used in this work to make the 

 digging easy because larger charges loosen the ground to such an extent 

 that it is difficult to make the poles or posts as firm as they should be. 

 This applies particularly to large poles. 



To do this blasting a hole is bored into the ground within 6 inches 

 of the desired depth of the hole. In the bottom of this hole from one- 

 quarter to a whole cartridge of Red Cross Extra Dynamite 40% is 

 exploded. No tamping should be done as this would cause the dynamite 

 to loosen the surrounding ground too much. 



Shattering Subsoil and Hardpan 



Plowing and cropping the same soil year after year robs the topsoil 

 of many of its original crop-bearing properties. Deep plowing as a rule 

 is the remedy for soil deterioration. When a subsoil plow is used a 

 noticeable increase in the crops is obtained although the soil is only 

 indifferently broken up to a maximum depth of 18 inches. How much 

 more then may be expected if 4 or 5 feet of virgin soil is rendered porous 

 and mellow ! Red Cross Extra Dynamite accomplishes this, as it thor- 

 oughly breaks up and shatters the hardpan, or hard impervious clay to 

 this depth. It aerates same and places at the disposal of plant life an 

 enlarged moisture reservoir and all the soluble fertilizing mineral ele- 

 ments contained in that virgin ground. 



In doing this work the greatest efficiency is obtained by boring holes 

 at intervals of 15 to 20 feet to a depth of 3 to 4 feet according to thickness 

 of the clay subsoil. Each hole is charged with one-half of a \% x 8-inch 

 cartridge of Red Cross Extra Dynamite 20%, primed with cap and fuse. 

 After the charge is placed, holes are tamped as compactly as possible up 

 to the surface. The tighter the tamping is done the better will the 

 results be and it is very important that this be done properly in order to 

 minimize as much as possible the effect of the explosion on the surface 

 soil. See page 122. 



When blasting hardpan the holes should be bored to within about 

 six inches of the bottom of the hardpan and the charge of dynamite 

 placed at that point, the object being to shatter the greatest area possible 

 and not to merely make a chamber in the ground under the hardpan. The 

 spacing of holes should be somewhat closer and charge of dynamite 

 should be somewhat heavier than when blasting ordinary subsoil. When 

 the hardpan is thin, six to twelve inches, the charge should be not more 

 than half a cartridge placed in the middle of the hardpan. 



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