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 the Mueseler, Landau and Yates lamps below. Such a lamp was known as a "protector" lamp, a term picked up and used as a company name. Only on the return to the bank could the lamp man open the lamp for refilling and service. Various different locking mechanisms were developed; miners tended to be ingenious in finding ways of circumventing them. A number of additional lamps were supposed to accompany each gang of men, but restricting the number was an obvious economy for the pit owners. The light given out by these lamps was poor (particularly the Davy where it