Davy lamp
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TheDavy lampis asafety lampused in flammable atmospheres, invented in 1815 by SirHumphry Davy.[1]It consists of awicklamp with the flame enclosed inside a mesh screen. It was created for use incoal mines,to reduce the danger of explosions due to the presence ofmethaneand other flammable gases, calledfiredamporminedamp.
History
[edit]German polymathAlexander von Humboldt,working for the German Bureau of Mines, had concerns for the health and welfare of the miners and invented a kind of respirator and "four lamps of different construction suitable for employment in various circumstances. The respirator was to prevent the inhaling of injurious gases, and to supply the miner with good air; the lamps were constructed to burn in the most inflammable kind offire-dampwithout igniting the gas. They were the forerunners of Davy's later invention, and were frequently made use of by the miners. "[2]
Davy's invention was preceded by that ofWilliam Reid Clanny,an Irish doctor atBishopwearmouth,who had read a paper to theRoyal Societyin May 1813. The more cumbersome Clanny safety lamp was successfully tested at Herrington Mill, and he won medals, from theRoyal Society of Arts.[3]
Despite his lack of scientific knowledge, engine-wrightGeorge Stephensondevised a lamp in which the air entered via tiny holes, through which the flames of the lamp could not pass. A month before Davy presented his design to the Royal Society, Stephenson demonstrated his own lamp to two witnesses by taking it downKillingworth Collieryand holding it in front of a fissure from whichfiredampwas issuing.[4]
The first trial of a Davy lamp with a wire sieve was atHebburnColliery on 9 January 1816.[5]A 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,[6]and a paper describing the lamp was formally presented at a Royal Society meeting in London on 9 November.[7]For it, Davy was awarded the society'sRumford 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 to his preferred solution).[7]For his invention Davy was given £2,000 worth of silver (the money being raised by public subscription), whilst Stephenson was accused of stealing the idea from Davy, because the fully developed 'Geordie lamp' had not been demonstrated by Stephenson until after Davy had presented his paper at the Royal Society, and (it was held) previous versions had not actually been safe.[6][8][a]
A local committee of enquiry gathered in support of Stephenson exonerated him, showing that he had been working separately to create the Geordie lamp,[10]and raised a subscription for him of £1,000.[11]Davy and his supporters refused to accept their findings, and would not see how an uneducated man such as Stephenson could come up with the solution he had: Stephenson himself freely admitted that he had arrived at a practical solution on the basis of an erroneous theory.[11]In 1833, aHouse of Commonscommittee found that Stephenson had equal claim to having invented the safety lamp.[11]Davy went to his grave claiming that Stephenson had stolen his idea. The Stephenson lamp was used almost exclusively inNorth East England,whereas the Davy lamp was used everywhere else. The experience gave Stephenson a lifelong distrust of London-based, theoretical, scientific experts.[12][b]
Design and theory
[edit]![](https://upload.wikimedia.org/wikipedia/commons/thumb/8/81/Pieler_safety_lamp.jpg/170px-Pieler_safety_lamp.jpg)
The lamp consists of awicklamp with the flame enclosed inside a mesh screen. The screen acts as aflame 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 fuelled by oil or naphtha (lighter fluid).[13]
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 ascarbon 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 damporchokedamp). 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.[citation needed]
Impact
[edit]In 1816, theCumberland Pacquetreported a demonstration of the Davy lamp at William Pit, Whitehaven. Placed in a blower "... the effect was grand beyond description. At first a blue flame was seen to cap the flame of the lamp, – then succeeded a lambent flame, playing in the cylinder; and shortly after, the flame of the firedamp expanded, so as to completely fill the wire gauze. For some time, the flame of the lamp was seen through that of the firedamp, which became ultimately extinguished without explosion. Results more satisfactory were not to be wished..."[14]Another correspondent to the paper commented "The Lamp offers absolute security to the miner... With the excellent ventilation of theWhitehaven Collieriesand the application of Sir HUMPHRY's valuable instrument, the accidents from the explosion of' (carburetted) 'hydrogene which have occurred (although comparatively few for such extensive works) will by this happy invention be avoided ".[14]
However, this prediction was not fulfilled: in the next thirty years, firedamp explosions in Whitehaven pits killed 137 people.[15]: 139 More generally, the Select Committee on Accidents in Mines reported in 1835 that the introduction of the Davy lamp had led to an increase in mine accidents;[11]: 130 the lamp encouraged the working of mines and parts of mines that had previously been closed for safety reasons.[16]For example, in 1835, 102 men and boys were killed by a firedamp explosion in a Wallsend colliery working the Bensham seam, described at the subsequent inquest byJohn Buddleas "a dangerous seam, which required the utmost care in keeping in a working state", which could only be worked with the Davy lamp. The coroner noted that a previous firedamp explosion in 1821 had killed 52, but directed his jury that any finding on the wisdom of continuing to work the seam was outside their province.[17]
The lamps had to be provided by the miners themselves, not the owners, as traditionally the miners had bought their own candles from the company store. Miners still preferred the better illumination from a naked light, and mine regulations insisting that only safety lamps be used[15]: 139 were draconian in principle, but in practice neither observed nor enforced. After two accidents in two years (1838–39) in Cumberland pits, both caused by safety checks being carried out by the light of a naked flame, theRoyal Commission on Children's Employmentcommented both on the failure to learn from the first accident, and on the "further absurdity" of "carrying a Davy lamp in one hand for the sake of safety, and a naked lighted candle in the other, as if for the sake of danger. Beyond this there can be no conceivable thoughtlessness and folly; and when such management is allowed in the mine of two of the most opulent coal-proprietors in the kingdom, we cease to wonder at anything that may take place in mines worked by men equally without capital and science"[15]: 140
Another reason for the increase in accidents was the unreliability of the lamps themselves. The bare gauze was easily damaged, and once just a single wire broke or rusted away, the lamp became unsafe. Work carried out by a scientific witness and reported by the committee showed that the Davy lamp became unsafe in airflows so low that a Davy lamp carried at normal walking pace against normal airflows in walkways was only safe if provided with a draught shield[18]: 13–17 (not normally fitted), and the committee noted that accidents had happened when the lamp was "in general and careful use; no one survived to tell the tale of how these occurrences took place; conjecture supplied the want of positive knowledge most unsatisfactorily; but incidents are recorded which prove what must follow unreasonable testing of the lamp; and your Committee are constrained to believe that ignorance and a false reliance upon its merits, in cases attended with unwarrantable risks, have led to disastrous consequences"[11]: 131 The "South Shields Committee", a body set up by a public meeting there[19](in response to an explosion at the St Hilda pit in 1839)[20]to consider the prevention of accidents in mines had shown that mine ventilation in the North-East was generally deficient, with an insufficient supply of fresh air giving every opportunity for explosive mixtures of gas to accumulate.[18]: 28–36 [c]A subsequent select committee in 1852 concurred with this view; firedamp explosions could best be prevented by improving mine ventilation (by the use of steam ejectors: the committee specifically advised against fan ventilation), which had been neglected because of over-reliance on the safety of the Davy lamp.[21]: viii
The practice of using a Davy lamp and a candle together was not entirely absurd, however, if the Davy lamp is understood to be not only a safe light in an explosive atmosphere, but also a gauge of firedamp levels. In practice, however, the warning from the lamp was not always noticed in time, especially in the working conditions of the era.[22]
TheRegulation and Inspection of Mines Actof 1860 therefore required coal mines to have an adequate amount of ventilation, constantly produced, to dilute and render harmless noxious gases so that work areas were – under ordinary circumstances – in a fit state to be worked (areas where a normally safe atmosphere could not be ensured were to be fenced off "as far as possible" ): it also required safety lamps to be examined and securely locked by a duly authorised person before use.[citation needed]
Even when new and clean, illumination from the safety lamps was very poor,[23]and the problem was not fully resolved until electric lamps became widely available in the late 19th century.[24]
Successors
[edit]A modern-day equivalent of the Davy lamp has been used in theOlympic flametorch relays. It was used in the relays for the Sydney, Athens, Turin, Beijing, Vancouver and Singapore YouthOlympic Games.It was also used for the Special Olympics Shanghai, Pan American and Central African games and for theLondon 2012 Summer Olympicsrelay.[25]
Lamps are still made inEccles, Greater Manchester;[26]inAberdare,South Wales;[27]and inKolkata,India.[28]
A replica of a Davy lamp is located in front of the ticket office at theStadium of Light(Sunderland AFC) which is built on a former coal mine.
In 2015, the bicentenary of Davy's invention, the formerBersham Colliery,inWrexham,Wales, now a mining museum, hosted an event for members of the public to bring in their Davy lamps for identification.[29]TheNational Mining Museum ScotlandatNewtongrange,Scotland, also celebrated the 200th anniversary of the invention.[30]In 2016, theRoyal Institution of Great Britain,where the Davy lamp prototype is displayed, decided to have the invention 3D scanned,reverse engineeredand presented to the museum visitors in a more accessible digital format via a virtual reality cabinet. At first sight it appears to be a traditional display cabinet but has a touch screen with various options for visitors to view and reference the virtual exhibits inside.[31]
Notes
[edit]- ^The mean maximum quenching diameter (the maximum hole diameter through which a flame (not an explosion) will not pass) for drilled holes in 1/32 "thick brass plate was reported in 1968 to be 0.139 inches for methane/air mixtures.[9]Davy's letter read at the 3 November meeting in Newcastle reported that his work on samples of firedamp had shown thatexplosionsin flammable mixtures of firedamp with air would not pass through tubes of diameter less than 1/8 ".[6]: 84 Stephenson's first lamp had a 1/2 "air inlet, throttled by a slider, the second three air inlets of internal diameter 3/22" (0.136 ") but distorted by bending at the tip to give an oval, long diameter 1/5", short diameter 1/14 ", in his third lamp, air ingress was through brass plates with holes of various sizes, the largest about 1/12" diameter[10]
- ^In his book 'George and Robert Stephenson,' the authorL.T.C. Roltrelates that opinion varied about the two lamps efficiency; that the Davy Lamp gave more light, but the Geordie Lamp was thought to be safer in a more gaseous atmosphere. He follows Smiles(1857) in referring to an incident in 1857 at Oaks Colliery in Barnsley where both lamps were in use. Following a sudden strong influx of gas the tops of all the Davy Lamps became red hot (which had in the past caused an explosion, and in so doing risked another), whilst all the Geordie Lamps simply went out.
- ^The Shields Committee argued that the local mines had had far too few shafts for the size of the underground workings (a view supported by evidence from George Stephenson, amongst others) and that the Commons Select Committee of 1835 had been misled on this point by gross over-estimates of the cost of additional shafts given them byJohn Buddle.The Shields Committee also argued against the practice (which it thought Parliament should legislate against for all new winnings) of sinking a single shaft and sub-dividing it by partitions ('brattices') to separate in- and out-flowing ventilation air – any explosion destroying the bratticing would destroy the ventilation of the mine and ensure the death by asphyxiation of those underground. This scenario had led to some of the deaths in the Wallsend accident of 1835: multiple shafts became a legal requirement in 1863 after the deaths of 204 miners in theHartley Colliery disasterof 1862 where the catastrophic failure of a pump beam both destroyed the ventilation and blocked the only means of escape.
References
[edit]- ^Brief History of the Miner's Flame Safety LampArchived26 August 2003 at theWayback Machineat minerslamps.net. Accessed 7 July 20121
- ^Life of Alexander Von Humboldt, Vol. I(1872) Karl Bruhns (ed), Chapter III by Julius Lowenberg, p.152 in German. Translated to English in 1873 by Jane and Caroline Lassell.
in the public Domain via Library of CongressAccessed 21 Dec 2021
This article incorporatespublic domain materialfrom websites or documents of theLibrary of Congress.
- ^Knight, David (1992) Humphry Davy: Science and Power. Cambridge, Cambridge University Press, (Chapter 8: The Safety Lamp),ISBN0-631-16816-8
- ^Brandling, C J (chair) (1817),Report upon the claims of Mr. George Stephenson, relative to the invention of his safety lamp, by the committee appointed at a meeting holden in Newcastle on the First of November 1817,Newcastle: Emerson Charnley, p. 17
- ^Thompson, Roy (2004).Thunder underground: Northumberland mining disasters, 1815–1865.Landmark. p. 121.ISBN978-1-84306-169-4.Retrieved8 January2013.
- ^abcParis, John Ayrton(1831).The Life of Sir Humphry Davy, Late President of the Royal Society, Foreign Associate of the Royal Institute of France...: In 2 volumes.Vol. II. Colburn & Bentley.
- ^abDavy, Humphry (1816)."On the Fire-Damp of Coal Mines, and on Methods of Lighting the Mines So as to Prevent Its Explosion".Philosophical Transactions of the Royal Society of London.106:1.doi:10.1098/rstl.1816.0001.
- ^Stephenson, George (1817).A description of the safety lamp, invented by George Stephenson, and now in use in Killingworth Colliery(Second ed.). London.
- ^Grove, J R (1968)."The Measurement of Quenching Diameters and their Relation to the Flameproof Grouping of Gases and Vapours"(PDF).Third Symposium on Chemical Process Hazards with Special Reference to Plant Design LChem.E. Symposium Series.25.London: Institution of Chemical Engineers: 53. Archived fromthe original(PDF)on 11 October 2017.Retrieved30 April2017.
- ^abAnon (1817).Report upon the claims of Mr. George Stephenson, relative to the invention of his safety lamp.Newcastle: S. Hodgson.
- ^abcdeSmiles, Samuel(1857). "Chap. X.: Invents the" Geordy "Safety Lamp.".The Life of George Stephenson, Railway Engineer.London: John Murray. pp.95–132.
- ^Davies, Hunter(1975).George Stephenson: The Remarkable Life of the Founder of the Railways.Weidenfeld and Nicolson.ISBN0-297-76934-0.
- ^"Miners' Lamps".History of Lindal & Marton.Retrieved3 March2024.
- ^ab"untitled paragraphs".Cumberland Pacquet, and Ware's Whitehaven Advertiser.9 April 1816. p. 3.
- ^abcCumberland & Westmorland Antiquarian & Archaeological Society: Extra Series XXIV:Wood, Oliver (1988).West Cumberland Coal: 1600–1982/3.Kendal: Titus Wilson.ISBN095007795X.
- ^Christopher Lawrence,The power and the glory: Humphry Davy and Romanticism,reference in Andrew Cunningham and Nicholas Jardine,Romanticism and the SciencesCambridge: University Press, 1990 page 224
- ^Sykes, John (1835).An account of the dreadful explosion in Wallsend Colliery, on the 18th June, 1835, to which is added a list of explosions, inundations, &c. which have occurred in the Coal Mines of Northumberland and Durham...Newcastle: John Sykes.(Sykes was the publisher of theNewcastle Courant)
- ^abThe Report of the South Shields Committee, appointed to investigate the causes of Accidents in Coal Mines.London: Longman, Brown, Green, & Longmans. 1843.
- ^advertisement beginning"At A Public Meeting of the Inhabitants...".Durham County Advertiser.5 July 1839. p. 3.
- ^"Awful Loss of Life at South Shields".Newcastle Courant.5 July 1839. p. 2.
- ^Report from the Select Committee on Coal Mines, together with the Proceedings of the Committee, Minutes of Evidence, Appendix and Index.London: by order of the House of Commons. 1852.
- ^See note in "Successors" section of this WP article about the modern day use of the lamps.
- ^Smithsonian (October 2022)."Safety Lamps".Smithsonian Institution.Retrieved22 October2022.
- ^Smithsonian (October 2022)."Electric Lamps".Smithsonian Institution.Retrieved22 October2022.
- ^Peck, TomLet the flames begin: Beckham gets the home fires burningThe Independent,19 May 2012. Accessed 12 July 2012
- ^Protector Safety Lamp Company, Ecclesat Heritage Photo Archive. Accessed 7 July 2012
- ^Aberdare – Cambrian Lamp Works – E. Thomas & Williamsat Rhondda Cynon Taf Library Service. Accessed 7 July 2012
- ^J. K. Dey and SonsOfficial website. Accessed 7 July 2012
- ^Prior, Neil (26 September 2015)."Mining museum celebrates 200 years of Davy Lamps".BBC News.Archivedfrom the original on 8 January 2019.Retrieved17 February2016.
We're not especially interested in valuing them, most are only worth about £50 or £60, but some of the rarest and oldest examples can sell for over £500.
- ^"Celebrating 200 Years of the Flame Safety Lamp".National Mining Museum.Retrieved17 February2016.
- ^"3D scanning the original Davy Lamp".Physical Digital. 2 May 2016.Archivedfrom the original on 5 June 2016.Retrieved9 May2016.
Further reading
[edit]- James, Frank A.J.L. (2005)."How Big is a Hole?: The Problems of the Practical Application of Science in the Invention of the Miners' Safety Lamp by Humphry Davy and George Stephenson in Late Regency England"(PDF).Transactions of the Newcomen Society.75(2): 175–227.doi:10.1179/tns.2005.010.S2CID111936569.Archived(PDF)from the original on 27 September 2019.
External links
[edit]![](https://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png)
- Popular Science videoshowing an experiment that demonstrates the principle of the Davy lamp
- Edwards, EricThe Miners' Safety LampatPitt Rivers Museum,Oxford University
- Humphry DavyBrief bio at Spartacus Educational
- Martyn Poliakoff, Martyn Poliakoff."Davy's Lamp".The Periodic Table of Videos.University of Nottingham.