(4) Prepare as many primers as there are holes required. Primers 

 should be made in accordance with the instructions contained on page 

 using for this purpose one Victor No. 6 Electric Fuze. 



(5) Punch or bore a row of holes along the center line where the 

 ditch has to be made. Holes should be made vertically with a bar not 

 less than one and one-half inches in diameter, spaced 28 inches apart, and 

 sunk to a depth approximately within 6 inches of the desired depth of 

 the ditch. The number of holes bored for each blast should be consistent 

 with the capacity of the blasting machine to be used. 



(6) If the work is dry, charge the holes after they have all been 

 bored to save time. If a charge of more than one cartridge is required, 

 place the primed cartridge in last, and tamp well to top of the ground. 



If the work is in very wet or swamp soil it is very often advisable to 

 load the holes as soon as bored as wet shifting soil may refill the hole. 

 Xo tamping is required if cartridges are well covered with water. 



(7) Connect electric fuze wires in one of the ways illustrated on 

 page 146. 



(8) As soon as the last hole is charged stretch out leading wire and 

 connect same to electric fuze wires, caution everyone to retire and when 

 certain that every one is at a safe distance away connect leading wire to 

 blasting machine and fire. Never connect leading unre to blasting 

 machine until ready to fire. 



In this way ditches can be dug up to 9 feet wide at the top, 3 feet 

 wide at the bottom and 4*/2 feet deep for approximately 6c. per lineal 

 foot or 8c. per cubic yard. The top width depends on the depth, size of 

 the charge, kind of soil and consistency of same. When digging ditches 

 requiring a width of from 9 to 20 feet, two or three rows of holes are 

 necessary. The holes should be the same distance apart in the rows, 

 the same depth and charged with the same quantity and kind of dynamite 

 as for the narrower ditches. 



Note: If in doubt as to the proper depth of holes or charge, try a short 

 test blast of five to ten holes. 



If the first hole in the second or succeeding sections is spaced the regular 

 26 or 28 inches away from the end of the first blast, a ridge will be left at 

 that point in the finished ditch. To overcome this, place the first charge in 

 each string not more than a few inches . away from the end of the last blasted 

 section. 



In heavy dry soil it may prove advantageous to load at the bottom of each hole 

 one cartridge of Red Cross Extra 40% Dynamite, underneath the 20% load, the 

 idea being that the weaker dynamite will break the upper soil and the 40% will 

 then throw it out better than if 20% were used exclusively. It must be remembered 

 that the kind and condition of the soil greatly affect the work, hence no hard and 

 fast rules can apply. 



In strongly sodded soil, cutting the sod with a spade along the proposed sides 

 of the ditch help to produce a clean excavation. 



145 



