Denton, Greater Manchester and then abandoned. After hatting, the most important industry in Denton was the manufacture of lead-acid batteries by Oldham Batteries (Oldham & Son Ltd). In 1865, Joseph Oldham established a millwright general engineering shop and by 1887 this company was manufacturing machinery for the hat-making industry. Another important industry in the area was coal mining and shortly after 1887 the company began making machinery and equipment for this industry, which included miners' portable lamps. Up to this time, miners had always used the safety lamp devised in 1815 by Sir Humphry Davy (1778–1829) but this new battery-powered Davy lamp eventually
Safety lamp copper coated with a fusible metal. If the lamp gets too hot the metal melts and closes up the air holes, extinguishing the lamp. The lamp has been tested and according to Lupton ""successfully resisted every effort to explode it up to a velocity of more than 100 feet per second"". It was not until tungsten filaments replaced carbon that a portable electric light became a reality. An early pioneer was Joseph Swan who exhibited his first lamp in Newcastle upon Tyne in 1881 and improved ones in subsequent years. The Royal Commission on Accidents in Mines set up in