stop about 6 inches above the sand or gravel in shallow holes, and 12 to 

 18 inches in deep holes. It very often happens that holes have to be 

 bored to depths averaging from 15 to 30 feet before the water-absorbing 

 strata are reached and in order to do this it is necessary to use an ex- 

 tension auger. If the place where the holes are to be put down is covered 

 with water too deep to work in, the boring should be done from a raft 

 anchored in the proper position. It is much easier to operate the auger 

 through a hole in the center of the raft than over the side. As soon as 

 the hole has been bored to the required depth the auger is withdrawn and 

 a piece of 1^-inch pipe sufficiently long to reach the bottom of same 

 and 5 or 6 inches above the water level is inserted. Through this the 

 dynamite cartridges are dropped one at a time and pushed to the bottom 

 with a wooden tamping rod. A good firm push will hold each cartridge 

 in position. The last cartridge but one is primed with a Victor Water- 

 proof Electric Fuze and one cartridge is put on top of it to hold same in 

 place, as it is not advisable to give the primed cartridge too hard a push 

 with the tamping rod. 



When the hole has been charged the loading pipe is withdrawn and 

 slipped over the ends of the electric fuze wires, the leading wires are con- 

 nected on to the electric fuze wires, the joints being carefully protected 

 with insulating tape and the raft is poled to the shore or a safe distance 

 away from the hole while the leading wire is carefully paid out. The 

 outer ends of the leading wires are then attached to the blasting machine, 

 the operation of which explodes the charge. It is unnecessary to do any 

 tamping in this work if the holes are filled with water. The cartridges 

 should not be slit. The explosive to use is Red Cross Extra Dynamite 

 40%. The following table gives the approximate charge for holes of 

 different depths : 



Where the ground is swampy or ponds form in the wet season only 

 and dry up later in the year, the blasting should be done in the dry 

 season when a raft will not be required. This blasting should be done 

 just as described above except that it is necessary to tamp the charge 

 thoroughly unless the borehole fills up with water. In this work it is 



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