Du Pont farmer's handbook; instructions in the use of dynamite for clearing land, planting and cultivating trees, drainage, ditching and subsoiling . ing pipe is withdrawn and slipped over the endsof the electric fuze wires, the leading wires are connected on to theelectric fuze wires, the joints being carefully protected with insulatingtape and the raft is poled to the shore or a safe distance away from thehole while the leading wire is carefully paid out. The outer ends ofthe leading wires are then attached to the blasting machine, the opera-tion of which explodes the charge. It is unnecessa
Du Pont farmer's handbook; instructions in the use of dynamite for clearing land, planting and cultivating trees, drainage, ditching and subsoiling . ing pipe is withdrawn and slipped over the endsof the electric fuze wires, the leading wires are connected on to theelectric fuze wires, the joints being carefully protected with insulatingtape and the raft is poled to the shore or a safe distance away from thehole while the leading wire is carefully paid out. The outer ends ofthe leading wires are then attached to the blasting machine, the opera-tion of which explodes the charge. It is unnecessary to do any tamp-ing in this work if the holes are filled with water. The cartridgesshould not be slit. The best explosive to use is Red Cross Extra40% Dynamite. The following table gives the approximate chargefor holes of different depths: DEPTH OF HOLE APPROXIMATE NUMBER OFl;4x8 CARTRIDGES 5 ft. 4 10 ft. 7 15 ft. 12 20 ft. 17 30 ft. 25 40 ft. 35 Where the ground is swampy or ponds form in the wet seasononly and dry up later in the year, the blasting should be done in thedry season when a raft will not be required. This blasting should be 54. ROAD WORK WITH DYNAMITE done just as described above except that it is necessary to tamp thecharge thoroughly unless the bore hole fills up with water. In thiswork it is sometimes of advantage to make a chamber in the bottomof the hole by first exploding a single cartridge in the bottom. Thismakes it possible to get more of the main charge in to the bottom andbreak the rock or subsoil better. The explosion of the single cartridgemay close the hole a little, but it can easily be opened again with theauger or an iron rod. The main charge must never be loaded im-mediately after chambering, but a half hour or more allowed for thebottom of the bore hole to cool off. This plan of chambering thebottom may also be followed when water fills the bore holes. See pages II to 1 5 for proper methods of priming, charging,tamping and firing. ROAD BUILDI
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Keywords: ., bookcentury1900, bookdecade1910, bookiddup, booksubjectexplosives
