Page 100 - Demo

98Charles Hall%u2019s InventionBanner Rock Products (Plant #1.), Alexandria%u2014Madison Co. (717.14)Banner Rock Products (Plant #2.), Alexandria%u2014Madison Co. (797.04)It was in 1896 that Charles Hall began his rockmelting experiments in Alexandria. Within a short period of time, he had invented a brand new product called rock wool%u2014and erected a factory on the south side of town to manufacture it. Rock wool (also called mineral wool) is made by blowing steam through molten limestone to produce fine strands of insulation. It soon became widely used for both insulation and soundproofing. In 1897 Hall formed his first business%u2014Crystal Chemical Co. By 1906, he had built a new factory and changed the name to Banner Rock Products. This structure was made almost entirely of concrete%u2014except for the roof. It was partially ripped off by a tornado in 1922. This was Plant #1. Because the demand for rock-wool insulation continued to grow, it was followed by a larger, more modern Plant #2, on the north side of town.In January 1929 (only months before the Great Depression), Hall sold his business to Johns-Manville Corp.%u2014then the largest producer of insulation in the world. Soon it built a new, larger facility and, eventually, the old Banner Rock buildings were retired. Today, Manville%u2014widely known as a manufacturer of fiberglass insulation%u2014no longer has any operations in Alexandria.As I took pictures, I saw only a few pieces of equipment scattered about%u2014a beat-up file cabinet, part of an old blower, piles of pallets, a mangled bicycle. In Plant #2, I found a single locker sitting, forlornly, inside one of the cavernous buildings. It made the emptiness seem more poignant.