This chapter singles out four major but very different industries for detailed spatial analysis. Iron and steel manufacturing is Britain's greatest traditional heavy industry. Basically, it consists of three distinctive activities - the smelting of pig iron in a blast furnace charged with iron ore, coking coal, limestone and some scrap; the refining of the pig iron into steel by removal of impurities, traditionally in an open-hearth furnace but increasingly today either in a large-scale vessel or converter through which is blown oxygen, or in an electric-arc furnace; and the rolling and shaping of the steel into strips, plates, girders, tubes or other pieces. Iron and steel manufacturing was of course the foundation of Britain's nineteenth-century industrial growth. Since about 1960, however, the relevance of the center-periphery model as an explanation of locational change in the motor vehicle industry has weakened substantially. Spatially, the electronic engineering industry as a whole is notable for its relatively high index of concentration.