In 1873, the Cotton Powder Company built a factory to produce gun cotton on Uplees Marsh. In 1912, a second factory was built by the Explosives Loading Company, with a third by Eley Brothers Ltd. established nearby at Harty Ferry.
The text describes the establishment of factories for producing gun cotton in different locations over time: Uplees Marsh (Cotton Powder Company), Harty Ferry (Eley Brothers Ltd.), and a second location near Harty Ferry (Explosives Loading Company).