Michael Smurthwaite having made preparation for a blast in the stone, working downwards or sinking, fastened a rope, called the centre line, in the hole, for the purpose of running a hot iron ring from the top of the pit to a train of gunpowder, and being drawn up from the bottom so as to be considered safe, the ring was run down the line by the other man William Wilson, which caused the explosion, and they were both lost. Wilson had gone to work that day for another man whose turn it was.

(an early reference to the use of gunpowder underground)