History of anthracite coal mining in Pennsylvania railroad system made transporting the anthracite exponentially easier, and by the 1860s anthracite coal was regularly supplying urban centers like Philadelphia and New York City and was helping to fuel the American Industrial Revolution. Anthracite and bituminous coal were formed in the eastern and western regions of Pennsylvania respectively during the Pennsylvanian time in the Carboniferous Geological Period (“History of Anthracite Coal Mining”). The Pennsylvania Anthracite Region is in the Valley and Ridge Province of the Appalachian Mountains, with the coal located in the folded and faulted terrain of the Province. The anthracite fields are maintained in synclinal basins that
What is a Masterpiece? confluence of memories and emotions forming a single idea", that it has "a power of recreating traditional forms so that they become expressive of an artist's own epoch and yet keep a relationship to the past". The highest masterpieces are said to be "illustrations of great themes." Clark also implicitly excluded the erotic from considerations of what constituted a masterpiece, based on his perspective that a necessary condition is the balance between sense and form (works that are too sensual are, therefore, unbalanced and not to be categorised at masterpiece level). What is a Masterpiece? What is a Masterpiece? is