Changes

The [[mining]] of coal as a [[fuel]] sparked the [[Industrial Revolution]], as coal was used to power [[factory|factories]] and [[railway]]s, first through the generation of steam, and later when coal became one of several methods of generating [[electricity]].

The [[mining]] of coal as a [[fuel]] sparked the [[Industrial Revolution]], as coal was used to power [[factory|factories]] and [[railway]]s, first through the generation of steam, and later when coal became one of several methods of generating [[electricity]].

Laboratory experiments show that coal can be formed in a matter of months, and with temperatures in the range of 100 to 150 degrees Celsius for brown coal and 400 degrees Celsius for black coal.<ref>Quoted by Walker, 2001</ref>

Laboratory experiments show that coal can be formed in a matter of months, and with temperatures in the range of 100 to 150 degrees Celsius (212-302 degrees Fahrenheit) for brown coal and 400 degrees Celsius (752 degrees Fahrenheit) for black coal.<ref>Quoted by Walker, 2001</ref>

== Types of coal ==

== Types of coal ==