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 where helmet (cap) lamps had been the norm. Nowadays, safety lamps are mainly electric, and traditionally mounted on miners' helmets (such as the wheat lamp) or the Oldham headlamp, sealed to prevent gas penetrating the casing and being ignited by electrical sparks. Although its use as a light source was superseded by electric lighting, the flame safety lamp has continued to be used in mines to detect methane and blackdamp, although many modern mines now also use sophisticated electronic gas detectors for this purpose. As a new light source, LED has many advantages for safety lamps, including longer illumination times