The bloomery was the earliest form of smelter capable of smelting iron. All indigenous African iron smelting processes are variants of the bloomery process. All traditional sub-Saharan African iron smelting processes are variants of the bloomery process. Early iron-production from bog ore mostly occurred in bloomery furnaces. One of the fragments was made of bloomery iron rather than meteoritic iron. In Roman times, workers reduced ore in a bloomery furnace. The bloomery furnace produced iron in a solid state. The product of the bloomery process is heterogeneous blooms of entrapped slag. Examples are the bloomery furnace and the blast furnace. The blast furnace operates as a countercurrent exchange process whereas a bloomery does not. The Catalan Forge was a variety of powered bloomery. Called the bloomery process, it produced very soft but ductile wrought iron. Trompes were used to provide compressed air for bloomery furnaces in Catalonia and the USA. The step from bloomery to true blast furnace is not big. The bloomery was charged with charcoal and iron ore and then lit.