This is from a wonderful book At the Works, by Lady Bell, about the town of Middlesborough and its ironworks; she was a member of one of the Quaker families that ran the works and she spent a lot of time investigating the living conditions of the workers and their families.
“The slag – the dross of the iron… flows either into ladles or into round vessels called ‘bogies’. The slag flowing into the latte hardens in cooling into what are commonly called slag ‘balls’, though, of course, they are not balls but short broad cylinders. These ladles are then taken along a railway-line to various places, where they are ‘tipped’ – that is, emptied out on to heaps, which eventually form embankments. A frequent sight on a winter’s night, one of the sights by which one ‘visualizes’ the iron works, is a slag ball bursting as it is tipped, and flaming up into a mass of flying fragments as it rolls down. The sides of these embankments, with the brittle jagged edges of the slag, sharp as glass, are the places where children of the ironworkers clamber up and down, as well content, apparently, as the more fortunate children who are rolling down a grassy slop. But a slip in these jagged edges means something very different from a slide and a roll down a gassy slope; and the children playing on the slag ‘tip are face to face with a daily danger, which grows more dangerous, and not less, as familiarity with it makes them more heedless.
These log grey bare headlands do at last, with the passing of time, become gradually clothed with green, but not till they have stood for many years. It is a parody of scenery, at best, amongst which the children of the iron works grow up. The world of the ironworks is one in which there are constant suggestions of the ordinary operations of life raised to some strange, monstrous power, in which the land runs, not with water, but with fire, where the labourer leading on his spade is going to dig, not in fresh, moist earth, but in a channel of molten flame; where, instead of stacking the crops, he stacks iron too hot for him to handle; where the tools laid out ready for his use are huge iron bars 10 feet or more, taking several men to wield them. The onlooker, whose centre of activity lies among surroundings different from these, walks with wonder and misgiving through the lurid, reverberating works, seeing danger at every turn, and shudders at what seems to him the lot of the worker among such grim surroundings as these. But there is many a man employed at the works to whom these surroundings are even congenial, to whom the world coloured in black and flame-colour is a world he knows and understands, and that he misses when he is away from it. And there must be hundred and thousands of people earning their livelihood in other ways, whose actual working hours are passed in a setting that would seem to many of us still less enviable: who, adding u figures or copying letters, see nothing but the walls of one small room round them for 8 hours every day. For the actual nature of the occupation of the various branches of ironmaking may appear to some of us, given the requisite strength and the requisite health, to be preferable to many other callings which might presumably have been open to the people engaged i it, or, indeed to those open to other classes of society who spend their lives in sedentary anxiety.”