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 to improve the perception of objects by 79.5%. Safety lamp A safety lamp is any of several types of lamp that provides illumination in coal mines and is designed to operate in air that may contain coal dust or gases both of which are potentially flammable or explosive. Until the development of effective electric lamps in the early 1900s miners used flame lamps to provide illumination. Open flame lamps could ignite flammable gases which collected in mines, causing explosions and so safety lamps were developed to enclose the flame and prevent it from igniting the surrounding atmosphere. Flame safety lamps