Editing Davy lamp (section)

== Design and theory ==
[[File:Pieler safety lamp.jpg|thumb|upright|A type of Davy lamp with apertures for gauging flame height]]
 
The lamp consists of a [[Candle wick|wick]] lamp with the flame enclosed inside a mesh screen. The screen acts as a [[flame arrestor]]; air (and any firedamp present) can pass through the mesh freely enough to support combustion, but the holes are too fine to allow a flame to propagate through them and ignite any firedamp outside the mesh. The Davy lamp was fueled by oil or naphtha (lighter fluid). <ref>{{cite web |url=http://www.lindal-in-furness.co.uk/MinersLamps/minerslamps.htm#:~:text=The%20flame%20safety%20lamp%20was,in%20a%20metal%20gauze%20cylinder. |title= Miners’ Lamps |author=<!--Not stated--> |date=|website=History of Lindal & Marton |publisher= |access-date=3 March 2024 |quote=}}</ref>

The lamp also provided a test for the presence of gases. If flammable gas mixtures were present, the flame of the Davy lamp burned higher with a blue tinge. Lamps were equipped with a metal gauge to measure the height of the flame. Miners could place the safety lamp close to the ground to detect gases, such as [[carbon dioxide]], that are denser than air and so could collect in depressions in the mine; if the mine air was oxygen-poor ([[asphyxiant gas]]), the lamp flame would be extinguished (''[[black damp]]'' or ''chokedamp''). A methane-air flame is extinguished at about 17% oxygen content (which will still support life), so the lamp gave an early indication of an unhealthy atmosphere, allowing the miners to get out before they died of asphyxiation.<ref>{{Cite web |title=Davy Lamp |url=https://www.woodlibrarymuseum.org/museum/davy-lamp/ |access-date=2025-02-26 |website=Wood Library-Museum of Anesthesiology |language=en-US}}</ref><ref>{{Cite web |title=Safety Lamps |url=https://americanhistory.si.edu/collections/object-groups/mining-lights-and-hats/safety-lamps |access-date=2025-02-26 |website=americanhistory.si.edu}}</ref>