Editing Watch (section)

=== Development ===
A rise in accuracy occurred in 1657 with the addition of the [[balance spring]] to the balance wheel, an invention disputed both at the time and ever since between [[Robert Hooke]] and [[Christiaan Huygens]]. This innovation significantly improved the accuracy of watches, reducing errors from several hours a day<ref>Milham 1945, p.226</ref> to approximately 10 minutes per day,<ref name="NIST">{{cite web|year= 2004|title= A Revolution in Timekeeping|work= A Walk Through Time|publisher= [[National Institute of Standards and Technology]]|url= https://www.nist.gov/pml/time-and-frequency-division/popular-links/walk-through-time/walk-through-time-revolution|access-date= 13 October 2022|archive-date= 13 October 2022|archive-url= https://web.archive.org/web/20221013184811/https://www.nist.gov/pml/time-and-frequency-division/popular-links/walk-through-time/walk-through-time-revolution|url-status= live}}</ref> which led to the introduction of the [[Clock face|minute hand]] on watch faces in Britain around 1680 and in France by 1700.<ref>{{Cite book|url= http://atena.beic.it/webclient/DeliveryManager?pid=13458392&search_terms=DTL59|title= Acta Eruditorum|year= 1737|location= Leipzig|pages= 123|access-date= 5 June 2018|archive-date= 3 July 2023|archive-url= https://web.archive.org/web/20230703114222/http://atena.beic.it/view/action/nmets.do?DOCCHOICE=13458392.xml&dvs=1688384463351~191&locale=en_US&search_terms=DTL59&show_metadata=true&adjacency=&VIEWER_URL=/view/action/nmets.do?&DELIVERY_RULE_ID=7&divType=|url-status= live}}</ref>

The increased accuracy of the balance wheel focused attention on errors caused by other parts of the [[movement (clockwork)|movement]], igniting a two-century wave of watchmaking innovation. The first thing to be improved was the [[escapement]]. The verge escapement was replaced in quality watches by the [[cylinder escapement]], invented by [[Thomas Tompion]] in 1695 and further developed by [[George Graham (clockmaker)|George Graham]] in the 1720s. Improvements in manufacturing – such as the tooth-cutting machine devised by [[Robert Hooke]] – allowed some increase in the volume of watch production, although finishing and assembling was still done by hand until well into the 19th century.
[[File:Blancpain_logo.svg|right|thumb|Founded in 1735, [[Blancpain]] is the oldest registered watch brand in the world.]]
A major cause of error in balance-wheel timepieces, caused by changes in [[Elasticity (physics)|elasticity]] of the [[balance spring]] from temperature changes, was solved by the bimetallic [[Balance wheel|temperature-compensated balance wheel]] invented in 1765 by [[Pierre Le Roy]] and improved by [[Thomas Earnshaw]] (1749–1829). The [[lever escapement]], the single most important technological breakthrough, though invented by [[Thomas Mudge (horologist)|Thomas Mudge]] in 1754<ref name="The Tourbillon Chronicles">{{cite web |last1=Forster |first1=Jack |title=The Tourbillon Chronicles: Birth Of The Tourbillon |url=https://www.the1916company.com/blog/tourbillon-origins.html |website=www.the1916company.com |access-date=2 October 2023}}</ref> and improved by Josiah Emery in 1785,<ref name="Timeline of Clocks and Watches">{{cite web |title=Timeline of Clocks and Watches |url=http://www.historyofwatch.com/clock-history/clock-timeline/ |website=History of Watch |access-date=2 October 2023}}</ref> only gradually came into use from about 1800 onwards, chiefly in Britain.<ref name="Neha S. Bajpai">{{cite web |last1=Bajpai |first1=Neha S. |title=An introduction to British watchmaking |url=https://wristcheck.com/discover/watch-101/an-introduction-to-british-watchmaking |website=WristCheck |access-date=2 October 2023}}</ref>
[[File:Acta Eruditorum - II orologi, 1737 – BEIC 13458392.jpg|thumb|A watch drawn in ''[[Acta Eruditorum]]'', 1737]]
The British predominated in watch manufacture for much of the 17th and 18th centuries, but maintained a system of production that was geared towards high-quality products for the élite.<ref>{{cite book|url= https://books.google.com/books?id=cVUSauNST8EC&q=British+Watch+Company+mass+production|title= Manufacturing Time: Global Competition in the Watch Industry, 1795–2000|author= Glasmeier, Amy|year= 2000|publisher= Guilford Press|isbn= 9781572305892|access-date= 7 February 2013|archive-date= 3 July 2023|archive-url= https://web.archive.org/web/20230703113711/https://books.google.com/books?id=cVUSauNST8EC&q=British+Watch+Company+mass+production|url-status= live}}</ref> The British Watch Company modernized clock manufacture with [[mass-production]] techniques and the application of duplicating tools and machinery in 1843. In the [[United States]],  [[Aaron Lufkin Dennison]] started a factory in 1851 in [[Massachusetts]] that used [[interchangeable parts]], and by 1861 a successful enterprise operated, incorporated as the [[Waltham Watch Company]].<ref name="Roe1916">{{citation | last = Roe | first = Joseph Wickham | title = English and American Tool Builders | publisher = Yale University Press | year = 1916 | location = New Haven, Connecticut | url = https://books.google.com/books?id=X-EJAAAAIAAJ | lccn = 16011753 | access-date = 12 November 2015 | archive-date = 3 July 2023 | archive-url = https://web.archive.org/web/20230703113712/https://books.google.com/books?id=X-EJAAAAIAAJ | url-status = live }}. Reprinted by McGraw-Hill, New York and London, 1926 ({{LCCN|27024075}}); and by Lindsay Publications, Inc., Bradley, Illinois, ({{ISBN|978-0-917914-73-7}}).</ref>