The cost of erecting machinery and establishing mines under such cir cumstances is great, and the operation of them expensive; while at best the coal can only be obtained at double the cost in ordinary mining opera tions in other thicker and more regular beds. But, in addition to all those serious drawbacks, when the mines are opened and the proprietors commencing to realize, a sudden stop is put to the production of coal by a downthrow, an upthrow, a fault, or a thinning of the seam, which may continue to an indefinite extent.
These difficulties, or, as the Richmond (Virginia) miners call them, "troubles," are always met with sooner or later, and almost invariably end in failure. Three feet of coal would pay well in the New England States if the seams were regular and pure; but under existing circumstances it is a question if any mode of mining would result profitably. The only rea sonable chances for success are in basins of moderate depth, where the surface indications of dip and uniform structure are favorable, and where the beds are not folded and distorted, but inclining at an angle of 35° or less, with uniform evenness of intervening strata.
Under such circumstances a company might be justified in fairly deve loping the resources of the anthracite fields of New England; and if ope rations are conducted with especial reference to the circumstances in which the coal exists, and one-half the area be productive of paying or workable seams, the result might be favorable, since the coal is worth $5 per ton at the mouth of the pit in that region, lying in the midst of the great Eastern markets.
To insure success, or to prove the availability of mining, exploring drifts or gangways should be pushed constantly forwards through coal or fault, in order to open enough of the mine to provide workable coal at all times, leaving the thin or unworkable portions as pillars, &c. By working the best portions of the coal and driving narrow gangways through the unpro ductive parts, there would be reasonable chances of success.