years in 2013 (in the US) and as a person ages vision degenerates. LED technology is physically robust compared to a filament light bulb, and has a longer life: 50,000 hours compared to 1,000 – 3,000. Extended life reduces light maintenance and failures; according to OMSHR an average of 28 accidents per year occur in US mines involving lighting. NIOSH has sponsored the development of cap lamp systems which they claim improve the "ability of older subjects to detect moving hazards by 15% and trip hazards by 23.7%, and discomfort glare was reduced by 45%". Conventional lights are strongly focussed in a beam, NIOSH LED lamps are designed to produce a wider more diffuse beam which is claimed to improve the perception of objects by 79.5%. See also Canaries as sentinels in coal mines Headlamp (outdoor) List of light sources Pellistor Wheat lamp References Bibliography The real author may be Thomas Unthank (NEIMME website). <!- (This volume disappeared from https://www.biodiversitylibrary.org/page/16221340. The Internet Archive's capture of that page shows no content because biodiversitylibrary pulls page images from IA. As of 2021-05, biodiversitylibrary lacks volumes 8 and 10.) (The Internet Archive's cataloged capture of the Google book is broken, showing p. 252a as p. 353 and omitting the real p. 353, at https://archive.org/details/annalsphilosoph09thomgoog/page/n378.) -> Publishers note: Portions of the article came from E. Thomas & Williams (see below). Command paper 4699 (ISBN refers to the David & Charles reprint of 1968 with an introduction by L. T. C. Rolt) (Sykes was the publisher of the Newcastle Courant) <!- (This volume disappeared from https://www.biodiversitylibrary.org/item/54758#page/5/mode/1up or http://biodiversitylibrary.org/page/16168936. The Internet Archive's capture of that page shows no content because biodiversitylibrary pulls page images from IA. As of 2021-05, biodiversitylibrary lacks volumes 8 and 10.) (The Internet Archive's cataloged capture of the Google book is clear, at https://archive.org/details/annalsphilosoph00thomgoog/page/n2.) -> (Presidential Lecture) Further reading North of England Institute of Mining and Mechanical Engineers, Nicholas Wood Memorial Library '"Miners safety lamps: a guide to resources". 2016. A guide to books, journals, government reports, archival material and other resources on lamps in the Institute Library. Barrie, D. The wand of science: a history of the British flame safety lamp. Birmingham: D. Barrie Risk Management Ltd, 2006. Barnard, T.R. Miners' safety lamps: their construction and care. London: Pitman, 1936. Galloway, R.L. Annals of coal mining and the coal trade. First series. [to 1835] London: Colliery Guardian, 1898 (reprinted Newton Abbot: