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 weak light though it was intrinsically safe provided it was kept upright. It was heavy and ungainly and required a man to pump it continuously. It was not a practical success and Clanny subsequently changed the basis of operation of later lamps in the light of the Davy and Stephenson lamps. Safety lamps have to address the following issues: Fire requires three elements to burn: fuel, oxidant and heat; the triangle of fire. Remove one element of this triangle and the burning will stop. A safety lamp has to ensure that the triangle of fire is maintained inside the lamp,