THE underground development of the State coal mine has depended largely on the data supplied by the bores, which were in the first place put down 20 chains apart; but, owing to the faulted nature of the field, it has been found expedient to bore much closer, especially in the line of main headings, to avoid mistakes in laying out the work. The daily output of 2400 tons is obtained from shafts, about 800 tons being hand-mined, and the other 1600 tons machine-cut coal. OCCURRENCE OF SEAM. The seam outcrops in several places, and has been proved by bores to a depth of 1200 ft. It has no regular inclination either in rate or direction, the rate varying from level to 1 in 3, whilst the direction is all round the compass, but the generally prevailing dip is to the south. The thickness varies from 1 ft. 6 in. to 10 ft. The seam is much faulted, the vertical displacements varying from a few inches to possibly 800 ft. The roof of the coal seam varies from very soft mudstone to a medium-hard sandstone, but generally speaking the roof improves with the depth of the seam. The floor of the seam is invariably a carbonaceous mudstone which swells and cuts Alp when water gets on it if the roadway is used for traffic.