(DOWNLOAD) "Tunneling in Rocks" by Ernest E. Wahlstrom # Book PDF Kindle ePub Free
eBook details
- Title: Tunneling in Rocks
- Author : Ernest E. Wahlstrom
- Release Date : January 02, 2012
- Genre: Engineering,Books,Professional & Technical,
- Pages : * pages
- Size : 10241 KB
Description
The beginnings of man's efforts to go underground by means of subterranean excavations are lost in the haze of antiquity, but there is abundant archeological evidence that in Europe Stone Age man sank shafts and drove tunnels to recover flint for the fabrication of sharp-edged implements such as knives, axes, arrowheads, and scrapers. Later, as an elementary knowledge of metallurgy was acquired by primitive people, possibly for the first time in central Asia, underground mining became necessary to supply the increasing demands for metals and alloys in technologically and culturally advancing civilizations. Very early underground excavations for metal-bearing ores have been identified in Caucasia, between the Black and Caspian Seas, and date back to approximately 3500 B.C. From this center and others of unknown location and through ever-expanding communication and trade, knowledge of mining and metallurgical techniques spread in all directions throughout the civilized world.
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