IT is not a long way back to the days when animal labour in the collieries was pursued under such conditions that no one with the least imagination could call them satisfactory. But the horse and the pony are rapidly vanishing before the development of the more adequate mechanical means of getting and transporting coal. Moreover, this development, together with the electrification of the collieries and the application of machinery to the preparation of coal for the market, has effected a vast enhancement of the standard of comfort of the workmen and of their wage-earning capacity.