A Primer on Explosives for Coal Miners

A Primer on Explosives for Coal Miners

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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1909 edition. Excerpt: ...not commended here) consist of copper capsules about as thick as an ordinary lead pencil, which are commonly charged with dry mercury fulminate or with a mixture of dry mercury fuhninate and potassium chlorate that is compressed in the bottom of the capsule, filling it to about one.third of its length. Dynamite and other detonating explosives are in practice fired by. means of detonators, for though they may be exploded of, ':::: : s_1" " by the aid of squibs or fuse, or by means of gun powder primers, yet the explosion so produced is not a complete one; the explosives are not used to their best advantage; all of the work that they can do is not done; and, moreover, the gases that are produced are usually dangerous. Where high explo sives are employed, it is safer to fire with detonators strong enough to cause their most complete explosion. Permissible explosives should be fired by detonators, and are best fired by electric detonators of the strength prescribed for each one. (See p. 61.) Action of fuse. Several grades of these blasting caps or detonators are to be found in the market, and they are differently designated by, o: ' _"d' ' d'"" different manufacturers. The "strengths" of the detonators most commonly used, as measured by the weights of the fulminating composition contained in them, are as follows: Grades of detonators and weight of their charges. Detonators are fired by the aid of a piece of fuse. The end of the fuse is inserted in the mouth of the blasting cap and tof: t;l; ' _dt""' carefully pushed down until it gently touches the surface of the detonating composition, and then the cap is crimped onto the fuse. (See Pl. VIII, A.) The cap, with the...show more

Product details

  • Paperback | 26 pages
  • 189 x 246 x 1mm | 68g
  • Rarebooksclub.com
  • United States
  • English
  • black & white illustrations
  • 1236799224
  • 9781236799227