Editing 1840s (section)

== Science and technology ==
[[File:Goodyear-Charles-LOC-closeup.jpg|thumb|115px|right| [[June 15]]: [[Charles Goodyear]].]]

=== Astronomy ===
* [[Eta Carinae]] is temporarily the second-brightest star in the night sky.
* [[September 23]], [[1846]] – [[Discovery of Neptune]]: The planet is observed for the first time by German astronomers [[Johann Gottfried Galle]] and [[Heinrich Louis d'Arrest]] as predicted by the British astronomer [[John Couch Adams]] and the French astronomer [[Urbain Le Verrier]].
* [[September 16]], [[1848]] – [[William Cranch Bond]] and [[William Lassell]] discover [[Hyperion (moon)|Hyperion]], [[Saturn]]'s [[natural satellite|moon]].

=== Photography ===

The 1840s saw the rise of the [[Daguerreotype]]. Introduced in 1839, the Daguerreotype was the first publicly announced photographic process and came into widespread use in the 1840s. Numerous events in the 1840s were captured by photography for the first time with the use of the Daguerreotype. A number of daguerreotypes were taken of the occupation of Saltillo during the Mexican–American War, in 1847 by an unknown photographer. These photographs stand as the first ever photos of warfare in history.

=== Telegraph ===
[[File:The first telegram. Professor Samuel Morse sending the despatch as dictated by Miss Annie Ellsworth.jpg|thumb|180px|The first telegram. Professor [[Samuel Morse]] sending the dispatch as dictated by Miss Annie Ellsworth]]
* The first [[electrical telegraph]] sent by [[Samuel Morse]] on May 24, 1844, from [[Baltimore, Maryland|Baltimore]] to [[Washington, D.C.]]

=== Computers ===
* [[1843]] – [[Ada Lovelace]] translates and expands [[Luigi Federico Menabrea|Menabrea]]'s notes on [[Charles Babbage]]'s [[analytical engine]], including an [[algorithm]] for calculating a sequence of [[Bernoulli numbers]], regarded as the world's first [[computer program]].<ref>{{cite journal|first1=John|last1=Fuegi|first2=Jo|last2=Francis|title=Lovelace & Babbage and the creation of the 1843 'notes'|journal=[[IEEE Annals of the History of Computing]]|volume=25|issue=4 |pages=16–26|doi=10.1109/MAHC.2003.1253887|date=October{{ndash}}December 2003}}</ref><ref>{{cite web|url=http://cs-www.cs.yale.edu/homes/tap/Files/ada-bio.html|title=Ada Byron, Lady Lovelace|access-date=2010-07-11| archive-url= https://web.archive.org/web/20100721013509/http://cs-www.cs.yale.edu/homes/tap/Files/ada-bio.html| archive-date= 21 July 2010 | url-status= live}}</ref><ref>{{cite journal|last=Menabrea|first=L. F.|author-link=Luigi Federico Menabrea|year=1843|title=Sketch of the Analytical Engine Invented by Charles Babbage|journal=[[Scientific Memoirs]]|volume=3|url=http://www.fourmilab.ch/babbage/sketch.html|access-date=2010-10-01| archive-url= https://web.archive.org/web/20100913042032/http://www.fourmilab.ch/babbage/sketch.html| archive-date= 13 September 2010 | url-status= live}}</ref>

=== Chemistry ===
* [[June 15]], [[1844]] – [[Charles Goodyear]] receives a [[patent]] for [[vulcanization]], a process to strengthen [[rubber]].
* [[1844]] – Swedish chemistry professor [[Gustaf Erik Pasch]] invents the [[safety match]].
* [[1846]] – [[Abraham Pineo Gesner]] develops a process to refine a liquid fuel, which he calls [[kerosene]], from [[coal]], [[bitumen]] or [[oil shale]].

=== Geology ===
* [[1840]] – [[Louis Agassiz]] publishes his ''Etudes sur les glaciers'' ("Study on Glaciers", 2 volumes), the first major scientific work to propose that the Earth has seen an [[ice age]].

=== Physics ===
* [[1840]] – The first English translation of Goethe's ''[[Theory of Colours]]'' by [[Charles Lock Eastlake|Charles Eastlake]] is published.
* [[1842]] – [[Julius Robert von Mayer]] proposes that [[work (thermodynamics)|work]] and [[heat]] are equivalent.<ref>{{cite journal|last=von Mayer|first=J. R.|year=1842|title=Bemerkungen über die Kräfte der unbelebten Nature ("Remarks on the forces of inorganic nature")|journal=[[Liebigs Annalen|Annalen der Chemie und Pharmacie]]|volume=43|issue=2|pages=233–40|doi=10.1002/jlac.18420420212|hdl=2027/umn.319510020751527|hdl-access=free}}</ref>
* [[October 16]], [[1843]] – [[William Rowan Hamilton]] discovers the calculus of [[quaternions]] and deduces that they are non-commutative.<ref>{{cite web|title=William Rowan Hamilton Plaque|url=https://www.geograph.org.uk/photo/347941|website=Geograph|year=2007|access-date=2011-03-08}}</ref>
* [[1843]] – [[James Joule]] experimentally finds the [[mechanical equivalent of heat]].<ref>{{cite journal|title=On the Mechanical Equivalent of Heat|last=Joule|first=J. P.|journal=[[Proceedings of the Royal Society|Abstracts of the Papers Communicated to the Royal Society of London]]|year=1843|volume=5|page=839|doi=10.1098/rspl.1843.0196|doi-access=free}}</ref>

=== Biology ===
[[File:Greatauk-london.jpg|thumb|115px|right| [[July 3]]: [[great auk]].]]
* [[July 3]], [[1844]] – The last definitely recorded pair of [[great auk]]s are killed on the [[Iceland]]ic island of [[Eldey]].
* [[1844]] – The anonymously written ''[[Vestiges of the Natural History of Creation]]'' is published and paves the way for the acceptance of [[Charles Darwin|Darwin]]'s book ''[[The Origin of Species]]''.

==== Paleontology ====
* [[1842]] – [[English people|English]] [[Palaeontology|palaeontologist]] [[Richard Owen]] coins the name ''Dinosauria'', hence the [[Anglicization|Anglicized]] ''[[dinosaur]]''.<ref>Owen, R. (1842). "Report on British Fossil Reptiles." Part II. Report of the British Association for the Advancement of Science, Plymouth, England.</ref>

=== Psychology ===
* [[November 13]], [[1841]] – Scottish surgeon [[James Braid (surgeon)|James Braid]] first sees a demonstration of ''[[animal magnetism]]'' by [[Charles Lafontaine]] in [[Manchester]], which leads to his study of the phenomenon that he (Braid) eventually calls ''[[hypnotism]]''.

=== Archaeology ===

* [[May 15]], [[1840]] – Discovered by several workmen, the [[Cuerdale Hoard]] becomes one of the largest haul of Viking-period jewellery, coins and other items totalling 8,600 finds.<ref>''Viking Age Archaeology'' 1995:46.</ref>

=== Economics ===
* [[June 20]], [[1842]] – Anselmo de Andrade, Portuguese economist and politician, is born in [[Vila Real de Santo António Municipality|Vila Real de Santo António]].
* [[August 28]], [[1844]] – [[Friedrich Engels]] and [[Karl Marx]] meet in [[Paris, France]].
* [[1845]] – [[Friedrich Engels]]' treatise ''[[The Condition of the Working Class in England in 1844]]'' is published in [[Leipzig]] as ''Die Lage der arbeitenden Klasse in England''.
* [[June 1]], [[1847]] – The first congress of the [[Communist League]] is held in London.
[[File:Communist-manifesto.png|thumb|[[February 21]]: [[Karl Marx]] publishes ''[[The Communist Manifesto]]''.]]
* [[February 21]], [[1848]] – [[Karl Marx]] and [[Friedrich Engels]] publish ''[[The Communist Manifesto]]'' (''Manifest der Kommunistischen Partei'') in London.

=== Medicine ===
* [[March 30]], [[1842]] – [[Anesthesia]] is used for the first time in an operation (Dr. [[Crawford Long]] performed the operation using [[diethyl ether|ether]]).
* [[December 27]], [[1845]] – Anesthesia is used for childbirth for the first time (Dr. Crawford Long in [[Jefferson, Georgia]]).
* [[November 4]] – [[November 8|8]], [[1847]] – [[James Young Simpson]] discovers the [[anesthetic]] properties of [[chloroform]] and first uses it, successfully, on a patient, in an [[obstetric]] case in [[Edinburgh]].<ref>First communicated to the Medico-Chirurgical Society of Edinburgh, November 10, and published in a pamphlet, ''Notice of a New Anæsthetic Agent'', in Edinburgh, November 12.</ref><ref>{{cite book|last=Gordon|first=H. Laing|title=Sir James Young Simpson and Chloroform (1811–1870)|url=https://books.google.com/books?id=pYer05UwKBYC|access-date=2011-11-11|year=2002|publisher=Minerva Group, Inc|isbn=978-1-4102-0291-8}}</ref>
* [[January 23]], [[1849]] – [[Elizabeth Blackwell (doctor)|Elizabeth Blackwell]] is awarded her M.D. by the Medical Institute of [[Geneva, New York]], thus becoming the [[United States]]' first woman doctor.

=== Technology ===

* 1840s – The [[Wenham Lake Ice Company]], in collaboration with [[Frederic Tudor]], played a pioneering role in the mass production and commercial distribution of ice on an industrial scale. This laid the groundwork for the eventual standardization of ice as a commonplace commodity for domestic and everyday use.<ref>{{Cite book |last=Bryson |first=Bill |url=http://archive.org/details/athomeshorthisto00brys |title=At Home: A Short History of Private Life |date= |publisher=Doubleday |others= |year=2010 |isbn=978-0-7679-1938-8 |location=New York |pages=71–73 |language=en}}</ref>
* 1845 – The [[Underwater]] [[telescope]] is patented by [[Sarah Mather]], permitting sea-going vessels to survey the depths of the ocean

[[File:Launch-of-the-SS-GB.jpg|thumb|The 1843 launch of the ''[[SS Great Britain|Great Britain]]'', the revolutionary ship of [[Isambard Kingdom Brunel]]]]

=== Exploration ===

==== Antarctica ====
* [[January 19]], [[1840]] – Captain [[Charles Wilkes]]' [[United States Exploring Expedition]] sights what becomes known as [[Wilkes Land]] in the southeast quadrant of [[Antarctica]], claiming it for the [[United States]] and providing evidence that Antarctica is a complete continent.<ref>{{cite web|url=http://www.quarkexpeditions.com/antarctica/exploration.shtml|title=Antarctic Exploration — Chronology|access-date=2006-10-20|publisher=Quark Expeditions|year=2004|archive-url=https://web.archive.org/web/20060908120017/http://www.quarkexpeditions.com/antarctica/exploration.shtml |archive-date=2006-09-08}}</ref>
* [[January 21]], [[1840]] – [[Dumont D'Urville]] discovers [[Adélie Land]] in [[Antarctica]], claiming it for [[France]].<ref>{{cite book|last=Guillon|first=Jacques|title=Dumont d'Urville|publisher=France-Empire|year=1986|location=Paris|isbn=978-2-7048-0472-6}}</ref>
* [[January 27]], [[1841]] – The active [[volcano]] [[Mount Erebus]] in [[Antarctica]] is discovered and named by [[James Clark Ross]].<ref>Ross, ''Voyage to the Southern Seas'', '''1''', pp. 216–8.</ref>
* [[January 28]], [[1841]] – Ross discovers the "Victoria Barrier", later known as the [[Ross Ice Shelf]]. On the same voyage, he discovers the [[Ross Sea]], [[Victoria Land]] and [[Mount Terror (Antarctica)|Mount Terror]].
* [[January 23]], [[1842]] – [[Antarctic]] explorer [[James Clark Ross]], charting the eastern side of [[James Ross Island]], reaches a [[Farthest South]] of 78°09'30"S.<ref>{{cite book|last=Coleman|first=E. C.|title=The Royal Navy in Polar Exploration, from Frobisher to Ross|publisher=Tempus Publishing|location=Stroud|year=2006|isbn=978-0-7524-3660-9|page=335}}</ref>
* [[January 6]], [[1843]] – [[Antarctic]] explorer [[James Clark Ross]] discovers [[Snow Hill Island]].

=== Transportation ===

==== Rail ====
[[File:James Pollard - The Louth-London Royal Mail Travelling by Train from Peterborough East, Northamptonshire - Google Art Project.jpg|thumb|The Louth-London [[Royal Mail]] travelling by train from [[Peterborough East railway station|Peterborough East]], 1845]]
Widespread interest to invest in rail technology led to a [[Stock market bubble|speculative frenzy]] in [[United Kingdom|Britain]], known there as [[Railway Mania]]. It reached its zenith in 1846, when no fewer than 272 [[Acts of Parliament]] were passed, setting up new railway companies, and the proposed routes totalled {{convert|9500|mi|km}} of new railway. Around a third of the railways authorised were never built – the company either collapsed due to poor financial planning, was bought out by a larger competitor before it could build its line, or turned out to be a fraudulent enterprise to channel investors' money into another business.

==== Steam power ====
[[File:Awful conflagration of the steam boat Lexington.jpg|thumb|right|230px| [[January 13]]: Steamship ''Lexington'' sinks.]]
[[File:RMS Britannia 1840 paddlewheel.jpg|thumb|210px|right|[[July 4]]: {{RMS|Britannia}}.]]
* [[July 4]], [[1840]] – The [[Cunard Line]]'s 700-[[ton]] wooden paddlewheel steamer {{RMS|Britannia}} departs from [[Liverpool]], bound for [[City of Halifax|Halifax]], [[Nova Scotia]], on the first steam transatlantic passenger mail service.<ref>{{cite book|last1=Palmer|first1=Alan|last2=Palmer|first2=Veronica|year=1992|title=The Chronology of British History|publisher=Century Ltd|location=London|pages=263–264|isbn=978-0-7126-5616-0}}</ref>
[[File:Ss Great Britain.jpg|thumb|200px|right| [[July 19]]: [[SS Great Britain|SS ''Great Britain'']] launch.]]
* [[July 19]], [[1843]] – [[Isambard Kingdom Brunel]]'s {{SS|Great Britain}} is launched from [[Bristol]]; it will be the first iron-hulled, propeller-driven ship to cross the [[Atlantic Ocean]].<ref>{{cite news|title=Royal Visit|work=The Bristol Mirror|pages=1–2|date=20 July 1843}}</ref>
* [[1843]] – The steam powered [[rotary printing press]] is invented by [[Richard March Hoe]] in the [[United States]].<ref>{{cite book|last=Meggs|first=Philip B.|author-link=Philip B. Meggs|title=A History of Graphic Design|publisher=Wiley|year=1998|edition=3rd|page=147|isbn=978-0-471-29198-5}} It receives {{US Patent|5199}} in [[1847 in science|1847]] and is placed in commercial use the same year.</ref>
* [[July 26]] – [[August 10]], [[1845]] – [[Isambard Kingdom Brunel]]'s iron [[steamship]] ''[[SS Great Britain|Great Britain]]'' makes the [[Transatlantic Crossing]] from [[Liverpool]] to [[New York City|New York]], the first [[Propeller|screw propelled]] vessel to make the passage.<ref>{{cite book|last=Fox|first=Stephen|year=2003|title=Transatlantic: Samuel Cunard, Isambard Brunel, and the Great Atlantic Steamships|publisher=HarperCollins|isbn=978-0-06-019595-3|url=https://archive.org/details/transatlanticsam00foxs}}</ref><ref>{{cite web|title=Great Britain |url=http://www.theshipslist.com/pictures/Greatbritain.htm |website=The Ships List |access-date=2010-10-01 |url-status=dead |archive-url=https://web.archive.org/web/20100528131641/http://www.theshipslist.com/pictures/Greatbritain.htm |archive-date=2010-05-28 }}</ref>

=== Other inventions ===
* [[October 5]], [[1842]] – [[Josef Groll]] brews the first [[pilsner]] beer in the city of [[Plzeň|Pilsen]], [[Bohemia]] (now the [[Czech Republic]]).
* [[September 10]], [[1846]] – [[Elias Howe]] is awarded the first United States patent for a [[sewing machine]] using a [[lockstitch]] design.<ref>{{US patent|4750}}</ref>