what is the use of cool mine

COAL – A Fossil Fuel - rocksandminerals However, commercial coal mines did not start operation until the 1740s in ia. The Industrial Revolution played a major role in expanding the use of coal. During the first half of the 1800s, the Industrial Revolution spread to the United States. Why did they put canaries in coal mines? - io9 In the old days, a canary went down to work with coal miners. The practice was so ubiquitous that it's become a cliche. But why, specifically, is a canary such a ... Coal Mining Methods - Colorado School of Mines Coal Mining Methods ... systems have been approved for use in several western coal mines because they provide better ground stability than the three-entry systems    Read More