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
Davy lamp letter from Davy (which he intended to be kept private) describing his findings and various suggestions for a safety lamp was made public at a meeting in Newcastle on 3 November 1815, and a paper describing the lamp was formally presented at a Royal Society meeting in London on 9 November. For it, Davy was awarded the Society's Rumford Medal. Davy's lamp differed from Stephenson's in that the flame was surrounded by a screen of gauze, whereas Stephenson's prototype lamp had a perforated plate contained in a glass cylinder (a design mentioned in Davy's Royal Society paper as an alternative