Obsolete Technologies: Gasification
Gasification was the process used to turn coal into natural gas. It was the light source and heat source for the early days of the Industrial Revolution. It provided light and heat at the turn of a knob and banished darkness and coal in a fashion that seemed magical, and yet is almost completely obsolete.
Steve Gunnell discussed these "lost" technologies in depth, getting to all the sticky, oily and often hazardous bits.