Editing Timeline of historic inventions (section)

====5th century====
{{see also|5th century#Inventions, discoveries, introductions}}
* '''400:''' The construction of the [[Iron pillar of Delhi]] in [[Mathura]] by the [[Gupta Empire]] shows the development of rust-resistant ferrous metallurgy in Ancient India,<ref>[http://home.iitk.ac.in/%7Ebala/journalpaper/journal/journalpaper_17.pdf ''On the Corrosion Resistance of the Delhi Iron Pillar''], R. Balasubramaniam, ''Corrosion Science'', Volume 42 (2000) pp. 2103–2129. ''Corrosion Science'' is a publication specialized in corrosion science and engineering.</ref><ref>{{cite book |author1=Yoshio Waseda |author2=Shigeru Suzuki | title = Characterization of corrosion products on steel surfaces |page=vii
|publisher=Springer | url =https://books.google.com/books?id=E_clmVK12YsC&q=iron+pillar+not+corrosive&pg=PR7 |isbn = 978-3-540-35177-1 |year = 2006}}</ref> although original texts do not survive to detail the specific processes invented in this period.
* '''5th century:''' The [[horse collar]] as a fully developed collar harness is developed in [[Northern and Southern dynasties]] [[China]] during the 5th century AD.<ref name="needham volume 4 part 2 28">Needham, Volume 4, Part 2, 28.</ref> The earliest depiction of it is a [[Dunhuang]] cave [[mural]] from the Chinese [[Northern Wei]] dynasty, the [[painting]] dated to 477–499.<ref name="needham volume 4 part 2 322">Needham, Volume 4, Part 2, 322.</ref>
* '''5th century – 6th century:''' [[Pointed arch bridge]] ([[Karamagara Bridge]]) in [[Cappadocia]], [[Eastern Roman Empire]]<ref>Galliazzo, Vittorio (1995): "I ponti romani", Vol. 1, Edizioni Canova, Treviso, {{ISBN|88-85066-66-6}}, p.&nbsp;92</ref><ref>Warren, John (1991): "Creswell's Use of the Theory of Dating by the Acuteness of the Pointed Arches in Early Muslim Architecture", ''[[Muqarnas (journal)|Muqarnas]]'', Vol. 8, pp.&nbsp;59–65 (61–63)</ref>
[[File:Nepali charka in action.jpg|thumb|A [[w:Demographics of Nepal|Nepali]] [[w:Spinning wheel|Charkha]] in action]]