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 ensure that the wick was lowered and the lamp extinguished by any attempt to open it. The lamp was "much more expensive than the forms of lamp now in general use, but Mr, Yates states that the saving of oil effected by its use will in one year pay the additional cost". The Evan–Thomas lamp is similar to a shielded Clanny, but there is a brass cylinder outside the gauze above the glass. It resists draughts well but the flame is dull. The Morgan is a cross between the Mueseler and the Marsaut. It is a shielded lamp with a