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 for illumination and Davys for testing. In particular "overmen ... whose lamps are mostly used to detect the presence gas, should avoid such [Clanny] lamps". The lamp is a modified Clanny designed by the Belgian Mathieu-Louis Mueseler. The flame is surrounded by a glass tube surmounted by a gauze capped cylinder. Air enters from the side above the glass and flows down to the flame before rising to exit at the top of the lamp. So far this is just a Clanny, but in the Mueseler a metal chimney supported on an internal gauze shelf conducts the combustion products to