The architectural remnants of the industrial age that shape our image of the 19th century were mostly used for coal processing or steel production. However, Bernd and Hilla Becher not only documented all varieties of this industrial heritage in individual photographs or typologies. They also paid photographic tribute to a much older tradition of industrial manufacturing: the so-called stone or crushing works. Stone and minerals have always been used for the construction of churches, houses, bridges, and roads. In Holland, for example, shells brought up from the seabed are still processed into shell limestone in bottle-shaped kilns today—a rather archaic method. In the stone processing industry, the raw material must be sorted, screened, crushed, milled, shaken, and agitated before it enters the kilns and is turned into Z.