Show EXAMINING A COAL FIELD in examining a coal field with a view to sale or purchase there are several things to consider besides the coal seam itself one of these is the distance from a town or a railroad and whether there is an available grade graae of not over 2 per cent for a branch line to the tipple of the coal mine the railroad yard near the tipple should d have a grade of 1 per cent in favor of the loaded cars next as to the location and availability of a tipple which will have a sufficient height above the railroad tracks and thirdly as to the available grade and length of a tramway from the mine to the tipple if the tipple is not located at the mines mouth available ground for the mine must also be considered in examining the coal seam itself its it average thickness is measured by a tape line and if the mine be opened to any depth the average thickness of the seam is estimated throughout the workings irregularities like rolls or pinches or faults are noted impurities like seams of bone or partings of shale must be carefully noted also their quantity thickness and relative position in the seam if near the top middle or bottum bottom the purity of a seam is an important virtue especially if the coal chafis Is to be shipped to the smelters shelters sm elters for smelting smelling sm elting purposes the smelters shelters sm elters are becoming more and more particular as to the amount of silica coming in with the coal as it seriously affects their metallurgical operations A band of shale may sometimes if the seam of coal is worked in two benches be carefully removed without materially con tribu ting to the impurities of the coal but not so the thin seams of bone which are inseparable from the coal and can only be removed by washing which often is not possible from lack of sufficiency lency of water in the dis district trIci the quality of the coal is determined from a sample taken takegi from top to bottom of the seam in the same manner as those taken in a vein of the precious metals and it is afterward analyzed or assayed by a competent assayer the quality of the roof is of importance whether of shale or sandstone in the latter case if the sandstone is firm and massive but little timber will be necessary if the shale is soft slacking and crumbling or liable to fall more timber will be required sometimes the shale or draw slate is sufficiently harband hard 1 and firm to form a good roof and requires little or no timbering the quality of the floor whether of shale or sandstone is also of importance whether rolling or even firm friable or swelling the average dip of the seam and strata must be taken carefully with a clinometer no ho and the direction of dip and strike with a compass if the workings go 90 to to the dip the loaded cars will have to be hauled up the grade if it is not too steep the pitch may be moderated by running L haulage ways diagonally across the dip if the dip is too steep for animal haulage alithe on the main entry then machinery will be necessary which involves steam and water parties having a property for sale should prepare the same prior to an examination by a mining engineer by opening up all the available seams to sufficient depth so as to show clearly their quality and character samples of analysis taken close to the outcrop are far from reliable and usually carry a far higher per cent of water and impurities than the coal really possesses with depth besides the different coal seams the character of the hill in which they occur is to be noticed whether the cover is heavy the rocks massive and apparently undisturbed by rolls faults or dikes or if the contrary is true the mining engineer endeavors to make a geological section of the hill and also a careful section of the coal seam showing the roof and floor and the number thickness and position of the seams of bone or shale partings business factors nily may be collected in the neighborhood or from the owners such as cost of labor transportation and the like the capacity or daily output of the mine in in e is an important factor and also its possibilities for increase and greater development there may be many seams in a property but usually only one or two are worked and these by reason of their superior purity or their accessibility commonly in the region in question it is the lower seams near the bottom of the hill rather than those higher up that are worked these usually are nearest to the level of the prairie on which the main railroad lines are estable established she d extract from article in december mines and and minerals by professor A lakes |