COAL MINING. 



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always move in these directions, unless they meet with a middle stratum 

 of air moving in a different direction. It, therefore, becomes a matter 

 of much greater consequence to meteorology than would at first view 

 appear, that the direction and velocity of these uppermost currents in 

 the atmosphere should be accurately ascertained. 



COAL MINING AT PITTSBURG. 



BY GEO. W. FAHNESTOCK. 



The great coal basin of the west, in which Pittsburg lies near the 

 northern out-crop, differs essentially from almost every other known. 

 The regulatity of its strata, the vastness of the bituminous deposits, 

 and the facility with which their treasures are brought forth, from 

 the bowels of the earth, have long been familiar in Geology. Every stu- 

 dent of that science is aware of the similarity existing between the coal 

 measures of the old world, while the important features, which distin- 

 guish an Appalachian coal field, are comparatively unknown. I do not 

 design, however, entering into more of its peculiarities than such as may 

 be elucidated in a loose sketch of the manner in which it is excavated 

 by the miners. Unlike the English collieries, or those of Eastern Penn- 

 sylvania, we never descend by a shaft for coal, although there are four 

 or five strata of from eighteen inches to six feet in thickness below the 

 level of the rivers. The lowest of these, as nearly as I remember, is 

 about three hundred feet below the river and was discovered while boring 

 for salt water. 



The vein usually worked, in the neighborhood of this city, lies about 

 three hundred feet above the river, and is only mined from the sides of 

 hills where the stratum is exposed. The miner digs into the coal and 

 examines its quality, whether it is hard, black, and shining, or soft, fria- 

 ble, and coated with a brown oxide of iron ; and if the test proves it to 

 be desirable coal, he prepares for an excavation. This stratum is about 

 six feet in thickness, and the floor is formed of pyritous shale, several 

 inches thick, under which a thickness of from nine inches to a foot of 

 good coal is found. This is never worked, owing to the cheapness and 

 abundance of the material. As they dig into the hill they confine them- 

 selves to a passage about six feet in width, planting strong posts oppo- 

 site each other every few feet, which support heavy timbers intended to 

 prevent the roof from caving in. These are always used, no matter how 

 far the miner goes, and if he ventures too far without a prop, he may for- 

 feit his life for his temerity, as the roof sometimes falls in a mass of 

 many tons weight, and without a moment's warning crushes all beneath. 

 An experienced miner by striking his pick against the roof, is enabled to 



