HOW TO HANDLE DYNAMITE.

Kaipara and Waitemata Echo, 1 May 1914, Page 7

HOW TO HANDLE DYNAMITE.

Accidents sometimes happen on the farm in connection with the use of dynamite. These are caused at times by careless handling, and at others by lack of definite knowledge of just how the operation should proceed when using the explosive.

The fact that dynamite is coming into use in connection with agricultural operations, and for work in the orchards, makes a knowledge of how to use it more imperative than has been the case hitherto.

The first question is the preparation of the hole, and this should 00 done with as little disturbance of the surrounding earth as possible by means of a crowbar driven in a slanting direction to the depth required. Care should always be taken to see that the hole, is large enough to admit the cartridges easily ; that is to say, the diameter of the hole should be l'-6in. to §in. larger than the diameter of the cartridge. If more than one cartridge is being used than the requisite number, press them gently, but firmly into the hole by means of a wooden tamping rod, which must not be pointed but cylindrical throughout. Press the cartridges home, so that the bottom of the borehole is solidly filled and no air space remains. One cartridge, known as the primer, is kept out.

Following this, prepare the fuse by cutting the end squarely off either with a sharp knife or a pair of nippers. Next the detonator should be taken and held between the thumb and. left finger with the loaded end

pointed away from the operator, and the square end of the fuse carefully inserted. If the borehole is damp the junction of the fuse with the detonator can be made watertight by the insertion of a little tought grease or some similar, material of suitable consistency, as it is important that no water or damp should get into the detonator between it and the fuse in order that there may be no miss-fire. Having inserted the fuse, it la then fixed by pressing the unloaded end of the cap round the fuse with a pair of nippers specially constructed for the purpose. Many miners are m the habit of using their teeth, but the proceeding is not a wise one, and not to be recommended.

j The question is next to insert the i detonator in the primer cartridge, : and a small hole should be made in j the cartridge with a pointed stick, or ; the handle of the nippers. The detonator is then pressed lightly in un- ; til about one-third of the copper j tube is left efposed outside the exj plosive. It is well that the fuse just above the detonator should be securely tied in position in the cartridge, so that it cannot be pushed too far j in, as otherwise there is no chance jof the fuse setting, fire to the cart- , ridge before the detonator can act. llt is1 well, also, to allow a good length of fuse, in order to give the . operator plenty of time to get away I after it has been fired.

In tamping the charge a lump of damp clay may be pressed in after the last cartridge, the usual tamping material toeing then used and pressed into the hole without using rough force. Packing firmly as with blasting powder is not necessary, all that is needed being to make the hole air-tight. A wooden tamping rod should be used, preferably of some wood which is*not too hard.