 The activities of Thomas Sr and Thomas Jr meant that they could not devote all their time to the colliery, so John's son Herbert Fletcher (1842–1895), also a member of Bolton town council, took control of the colliery and was named as the owner in the infamous court case over safety lamps.Herbert died of a heart attack at the colliery on 16 September 1895.Despite owning a coal mine, Herbert was active in the area of preventing smoke pollution and published several papers on smoke control, his most read being in the Journal of the Royal Society for the Promotion of Health.