Gas detector early detection methods relied on less precise detectors. Through the 19th and early 20th centuries, coal miners would bring canaries down to the tunnels with them as an early detection system against life-threatening gases such as carbon dioxide, carbon monoxide and methane. The canary, normally a very songful bird, would stop singing and eventually die if not removed from these gases, signaling the miners to exit the mine quickly. The first gas detector in the industrial age was the "flame safety lamp" (or Davy lamp) was invented by Sir Humphry Davy (of England) in 1815 to detect the presence of
Safety lamp the top of the lamp. Some Mueseler lamps were fitted with a mechanism which locked the base of the lamp. Turning down the wick eventually released the base, but by then the flame was extinguished and therefore safe. The lamp was patented in 1840 and in 1864 the Belgian government made this type of lamp compulsory. In the presence of firedamp the explosive mixture is drawn through two gauzes (cylinder and shelf), burnt and then within the chimney are only burnt gases, not explosive mixture. Like a Clanny, and the Davy before it, it acts as an indicator of firedamp,