§ Mr. D. DAVIESasked the Secretary for Mines the number of colliery explosions caused by the ignition of firedamp and the number caused by the ignition of coal dust during the last 10 years?
§ Mr. ISAAC FOOTOf the 136 colliery explosions involving loss of life during the years 1921–30, nearly all were explosions of firedamp. In one or two cases only was there any doubt whether firedamp or coal-dust was the original cause; and in only a few cases was an initial explosion of firedamp spread to any significant extent by a subsequent explosion of coal-dust.