Editing 1804 in science (section)

==Technology==
* February 21 – The [[Cornwall|Cornishman]] [[Richard Trevithick]]'s newly built "Penydarren" [[steam locomotive]] operates on the [[Merthyr Tramroad]] between [[Penydarren Ironworks]] in [[Merthyr Tydfil]] and [[Abercynon]] in [[South Wales]], following several trials since February 13, the world's first locomotive to work on rails.<ref>{{cite book|last=Rattenbury|first=Gordon|author2=Lewis, M. J. T.|title=Merthyr Tydfil Tramroads and their Locomotives|year=2004|publisher=[[Railway and Canal Historical Society]]|location=Oxford|isbn=0-901461-52-0}}</ref>
* The first [[Burr Truss]] bridge is built by [[Theodore Burr]] across the [[Hudson River]] in [[Waterford, New York]].<ref>{{cite web|title=The Burr Truss |work=Truss Styles of Covered Bridges |publisher=New York State Covered Bridge Society |url=http://www.nycoveredbridges.org/page44.html |accessdate=2011-12-13 |date=January 2006 |url-status=dead |archiveurl=https://web.archive.org/web/20060908112144/http://www.nycoveredbridges.org/page44.html |archivedate=2006-09-08 }}</ref>
* [[Joseph Marie Jacquard]] [[patent]]s the [[Jacquard machine]] to automate the [[loom]].<ref>{{Cite web|title=Programming patterns: the story of the Jacquard loom|url=https://www.scienceandindustrymuseum.org.uk/objects-and-stories/jacquard-loom|date=2019-06-15|access-date=2024-11-01|publisher=Science + Industry Museum}}</ref>
* [[Sir William Congreve, 2nd Baronet|William Congreve]] begins development of the solid-fuel [[Congreve rocket]] as an artillery weapon.
* The [[British Army]] first uses [[shrapnel shell]]s ("spherical case shot"), invented by Major [[Henry Shrapnel]], in action, against the Dutch in [[Suriname]].<ref>{{cite book|last=Hogg|first=O. F. G.|year=1970|title=Artillery: its origin, heyday and decline|location=London|publisher=Hurst|isbn=0-900966-43-2|page=180}}</ref>