- Underground in caves there was never really much need for running unless careful planning failed and a shaft fell in, or a patch of firedamp or bad air turned up.
- As the coal was worked, large cavities were left which filled with firedamp.
- Eruptions of natural gas were observed from very early times and the dangers of firedamp in mines were soon realized.
- The land, off Newhill Road in Monk Bretton, Barnsley, is one of the worst areas in the country to be affected by methane gas - known by miners as firedamp - leaching through the ground from disused mine workings.
- Once, 14-year-olds went down the pit and were vulnerable to explosions of firedamp and coal dust, to rock falls and inrushes of clay, sand and water.