Roman Empire

==Architecture and engineering==
{{Main|Ancient Roman architecture|Roman engineering|Roman technology}}

[[File:Colosseum in Rome, Italy - April 2007.jpg|thumb|The Flavian Amphitheatre, more commonly known as the [[Colosseum]]]]
The chief [[Ancient Roman architecture|Roman contributions to architecture]] were the [[arch]], [[Vault (architecture)|vault]] and [[dome]]. Some Roman structures still stand today, due in part to sophisticated methods of making cements and [[Roman concrete|concrete]].<ref>{{Cite book |last=MacDonald |first=William L. |title=The Architecture of the Roman Empire |date=1982 |publisher=Yale University Press |at=fig. 131B |author-link=William L. MacDonald}}; {{Cite journal |last1=Lechtman |first1=H. N. |last2=Hobbs |first2=L. W. |date=1987 |title=Roman Concrete and the Roman Architectural Revolution |journal=Ceramics and Civilization |volume=3 |pages=81–128}}</ref> [[Roman temple]]s developed [[Etruscan architecture|Etruscan]] and Greek forms, with some distinctive elements. [[Roman roads]] are considered the most advanced built until the early 19th century. The system of roadways facilitated military policing, communications, and trade, and were resistant to floods and other environmental hazards. Some remained usable for over a thousand years.{{Citation needed|date=February 2024}}

[[Roman bridges]] were among the first large and lasting bridges, built from stone (and in most cases concrete) with the arch as the basic structure. The largest Roman bridge was [[Trajan's bridge]] over the lower Danube, constructed by [[Apollodorus of Damascus]], which remained for over a millennium the longest bridge to have been built.<ref>{{cite web |url=http://www.britannica.com/eb/article-9008022/Apollodorus-Of-Damascus |title=Apollodorus of Damascus |website=Britannica |date=13 February 2024 |access-date=26 August 2012 |archive-date=21 May 2008 |archive-url=https://web.archive.org/web/20080521213321/http://www.britannica.com/eb/article-9008022/Apollodorus-Of-Damascus |url-status=live }}; {{Cite journal |last=Sarton |first=George |date=1936 |title=The Unity and Diversity of the Mediterranean World |journal=Osiris |volume=2 |doi=10.1086/368462 |pages=406–463 (430) |s2cid=143379839}}; {{Cite book |last1=Calcani |first1=Giuliana |title=Apollodorus of Damascus and Trajan's Column: From Tradition to Project |last2=Abdulkarim |first2=Maamoun |date=2003 |publisher=L'Erma di Bretschneider |isbn=978-88-8265-233-3 |page=11 }}; {{Cite book |last1=Yan |first1=Hong-Sen |title=International Symposium on History of Machines and Mechanisms: Proceedings of HMM 2008 |last2=Ceccarelli |first2=Marco |date=2009 |publisher=[[Springer Science+Business Media|Springer]] |isbn=978-1-4020-9484-2 |page=86}}</ref> The Romans built many [[List of Roman dams and reservoirs|dams and reservoirs]] for water collection, such as the [[Subiaco Dams]], two of which fed the [[Anio Novus]], one of the largest aqueducts of Rome.<ref>{{Cite journal |last=Smith |first=Norman |date=1970 |title=The Roman Dams of Subiaco |journal=Technology and Culture |volume=11 |issue=1 |doi=10.2307/3102810 |pages=58–68|jstor=3102810 |s2cid=111915102 }}; {{Cite book |last=Smith |first=Norman |title=A History of Dams |date=1971 |publisher=Peter Davies |isbn=978-0-432-15090-0 |page=26}}; {{Cite journal |last=Schnitter |first=Niklaus |date=1978 |title=Römische Talsperren |journal=Antike Welt |volume=8 |issue=2 |pages=25–32 (28)}}</ref>

[[File:Pont du Gard BLS.jpg|thumb|upright=1.3|The [[Pont du Gard]] aqueduct, which crosses the river [[Gardon]] in southern France, is on [[UNESCO]]'s list of [[World Heritage Site]]s.]]
The Romans constructed numerous [[Roman aqueduct|aqueducts]]. ''[[De aquaeductu]]'', a treatise by [[Frontinus]], who served as [[Curator Aquarum|water commissioner]], reflects the administrative importance placed on the water supply. Masonry channels carried water along a precise [[grade (slope)|gradient]], using [[gravity]] alone. It was then collected in tanks and fed through pipes to public fountains, baths, [[Sanitation in ancient Rome|toilets]], or industrial sites.<ref>{{Cite book |last=Chandler |first=Fiona |title=The Usborne Internet Linked Encyclopedia of the Roman World |date=2001 |publisher=Usborne Publishing |page=80}}</ref> The main aqueducts in Rome were the [[Aqua Claudia]] and the [[Aqua Marcia]].<ref>{{Cite book |last=Forman |first=Joan |title=The Romans |date=1975 |publisher=Macdonald Educational |page=34}}</ref> The complex system built to supply Constantinople had its most distant supply drawn from over 120&nbsp;km away along a route of more than 336&nbsp;km.<ref>{{Cite book |last=Crow |first=J. |chapter=Earth, walls and water in Late Antique Constantinople |date=2007 |title=Technology in Transition AD 300–650 |publisher=Brill |editor-last=Lavan |editor-first=L. |editor-last2=Zanini |editor-first2=E. |editor-last3=Sarantis |editor-first3=A.}}</ref> Roman aqueducts were built to remarkably fine [[Engineering tolerance|tolerance]], and to a technological standard not equalled until modern times.<ref>{{Cite book |last=Greene |first=Kevin |title=The Archaeology of the Roman Economy |date=1990 |publisher=University of California Press |isbn=978-0-520-07401-9 |page=39}}</ref> The Romans also used aqueducts in their extensive mining operations across the empire.{{Sfnp|Jones|Bird|2012|pp=59–74}}

[[Insulated glazing]] (or "double glazing") was used in the construction of [[thermae|public baths]]. Elite housing in cooler climates might have [[hypocaust]]s, a form of central heating. The Romans were the first culture to assemble all essential components of the much later [[steam engine]]: the crank and connecting rod system, [[Hero of Alexandria|Hero]]'s [[aeolipile]] (generating steam power), the [[Pneumatic cylinder|cylinder]] and [[piston]] (in metal force pumps), non-return [[valves]] (in water pumps), and [[Gear train|gearing]] (in water mills and clocks).<ref>{{Cite journal |last1=Ritti |first1=Tullia |last2=Grewe |first2=Klaus |last3=Kessener |first3=Paul |date=2007 |title=A Relief of a Water-powered Stone Saw Mill on a Sarcophagus at Hierapolis and its Implications |journal=Journal of Roman Archaeology |volume=20 |doi=10.1017/S1047759400005341 |pages=138–163 (156, fn. 74) |s2cid=161937987}}</ref>