of Porth, lower Rhondda Valley, Wales
George Insole and his son James Harvey Insole purchased the Cymmer Colliery in 1844.
Between 1852 and 1855, HM Inspector of Mines inspected the colliery twice and sent letters to Insole recommending safety improvements, in particular to the mine's underground ventilation system and the use of safety lamps underground.
On 15 July 1856 an explosion at the Old Pit mine of the Cymmer Colliery resulted in a "sacrifice of human life to an extent unparalleled in the history of coal mining of this country". 114 men and boys were killed. Thirty-five widows, ninety-two children, and other dependent relatives were left with no immediate means of support.
The immediate cause of the explosion was defective mine ventilation and the use of naked flames underground.
See Wikipedia entry for detailed information.
See Insole and Sons