The necessity for reduction in the cost and price of coal is considered, and the use of labour-saving machinery in the primary processes of winning coal is indicated as the most effective means by which the high labour cost can be substantially reduced.The evolution and early history of coal-cutters are outlined, the later developments of these machines a:e indicated, and the leading characteristics of the bar, chain and disc coalcutters are detailed.The nature of the service required of coal-cutters is explained, and the conditions under which the service is rendered are defined.Conveyors for underground use are described, and an outline is given of their place in the practice of intensive mining; first, in increasing the output per man at the coalface, and, second, as an aid to the reduction of the cost of transport of the coal from site to the mechanical haulage.An endeavour is made to indicate the respective spheres of electricity and compressed air for actuating coal-face machinery.