Upon his return in 1578 from Frobisher Bay in the Canadian Arctic with a reputed cargo of gold-bearing ore, Sir Martin Frobisher had the refining done on Powder Mill Lane in Dartford. However, the ore proved valueless and was used for road surfacing. Sir John Spilman set up the first paper mill in England at Dartford in 1588 on a site near Powder Mill Lane, and soon some 600 employees worked there, providing an invaluable source of local employment. Iron-making on the Weald was in full operation at this time, and iron ingots were sent to Dartford, to England's first iron-slitting mill, set up by the Darent at Dartford Creek in 1595 by Godfrey Box, an immigrant from the Low Countries. In 1785, John Hall, a millwright set up a workshop in Lowfield Street and began to make engines, boilers and machinery (some of it for the local gunpowder factory run by Miles Peter Andrews and the Pigou family), marking the foundation of J & E Hall, an engineering firm specialising in heavy engineering, and later refrigerating equipment, and, for 20 years from 1906, vehicle production, plus lifts and escalators.