Corps Papers And Memoirs On Military Subjects

Author : John Williams
Publisher : Rarebooksclub.com
ISBN 13 : 9781230177700
Total Pages : 58 pages
Book Rating : 4.1/5 (777 download)

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Download or read book Corps Papers, and Memoirs on Military Subjects; Compiled from Contributions of the Officers of the Royal Engineers and the East India Company's Engine written by John Williams and published by Rarebooksclub.com. This book was released on 2013-09 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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. 1849 edition. Excerpt: ...as to relative length and diameter, both of the platina firing wires, and the copper conducting wires. So that, when either of these conditions is fixed by the circumstances under which any particular explosion has to be conducted, the other conditions may be so suited to it as to produce the maximum effect. The conducting wires were then coiled, and tied to the side of the box, to protect them from injury, as they had to be carried to some distance. Two cartridges were placed in each box as a precautio in the event of a failure in one, or the fracture of either platinum wire. The powder having been put in, the top of the box was secured, pitched over, tightly roped, and covered with canvass. Thus completed, they were ready for carrying to the mine. As the charges were lowered into the shafts, the conducting wires were uncoiled and secured on the surface of the earth above. Two joists were laid on the bottom, on which the box was slid into the chamber, and on which it rested to keep it from the damp ground. The conducting wires were pressed into deep grooves cut for their reception in the side of the shaft; they were allowed to hang loosely within the chamber, and springing from under the box were close to the ground, so that they could not be injured if a falling in of the chamber should take place during the tamping, or previous to' the explosion. Before proceeding further, the charges were tested from the surface by the galvanometer; the chambers were then closed with strong boards, and the tamping commenced. Near the top of each shaft, two pickets 6 inches long were driven into the ground; a roughly constructed tin cup, to be filled with mercury, was screwed into each of these, and into them were plunged the ends of the conducting...