oculus (architecture)
{{Short description|Circular opening in the center of a dome or in a wall}}
{{Redirect|Oculi|the third Sunday in Lent|Lent{{!}}Oculi Sunday}}
File:Paris - Palais du Louvre - PA00085992 - 226 (oculus cropped).jpg oculus on the west facade of the Cour Carrée of the Louvre Palace, with figures of war and peace, sculpted by Jean Goujon and designed by Pierre Lescot, 1548{{cite book|last=Bresc-Bautier|first=Geneviève|title=The Louvre, a Tale of a Palace|date=2008|publisher=Musée du Louvre Éditions|isbn=978-2-7572-0177-0|page=122|url=}}]]
An oculus ({{etymology|la|{{wikt-lang|la|oculus}}|eye}}; {{plural abbr|oculi}}) is a circular opening in the center of a dome or in a wall. Originating in classical architecture, it is a feature of Byzantine and Neoclassical architecture.
A horizontal oculus in the center of a dome is also called opaion ({{etymology|grc|{{wikt-lang|grc|ὀπαῖον}} ({{grc-transl|ὀπαῖον}})|(smoke) hole}}; {{plural abbr|opaia}}).
Oeil-de-boeuf
File:Schloss Chenonceau Ochsenauge.jpg, France]]
File:Un œil de bœuf à Lyon (France).JPG (France)]]
File:Sutton Lodge, Brighton Rd, SUTTON, Surrey, Greater London (4).jpg Sutton Lodge in Sutton, London.[http://home2.btconnect.com/suttonlodge/history.php Sutton Lodge Day Centre website]]]
{{wiktionary | œil-de-bœuf}}
An oeil-de-boeuf ({{IPA|fr|œj.də.bœf|lang}}; {{langx|en|"bull's eye"}}), also œil de bœuf and sometimes anglicized as ox-eye window, is a relatively small elliptical window, typically for an upper storey, and sometimes set in a roof slope as a dormer, or above a door to let in natural light. These are relatively small windows, traditionally oval. The term is increasingly used for circular windows (in which case it could also be called an oculus), but not for holes in domes or ceilings.{{cite web|title=Oculus window |url=http://www.architecture.com/LibraryDrawingsAndPhotographs/Palladio/PalladianBritain/PalladianInteriors/PalladianPrinciples/Light/OculusWindow.aspx |archive-url=https://web.archive.org/web/20140327234516/http://www.architecture.com/LibraryDrawingsAndPhotographs/Palladio/PalladianBritain/PalladianInteriors/PalladianPrinciples/Light/OculusWindow.aspx |url-status=dead |archive-date=March 27, 2014 |date=March 27, 2014|website= Royal Institute of British Architects|access-date= 24 January 2014}}
Windows of this type are commonly found in the grand architecture of Baroque France. The term is also applied to similar round windows, such as those found in Georgian architecture in Great Britain, and later Greek Revival and Colonial Revival styles in North America, so that must be considered part of the usage. The term initially applied to horizontal elliptical windows, but is also used for vertical ones.Burden, Ernest E., Illustrated dictionary of architecture, McGraw-Hill Professional, 2001, p.354, {{ISBN|0-07-137529-5}}, {{ISBN|978-0-07-137529-0}}
[https://books.google.com/books?id=EGurZuDLZGUC&dq=Oeil-de-boeuf+window&pg=PA354 Google Books]
The spread is not limited to ecclesiastical architecture. This type of window can also be found in the late Romanesque period in the area of secular architecture in the castles of Frederick II of Hohenstaufen, Holy Roman Emperor from 1220 to 1250, (Castel del Monte, Palazzo San Gervasio, on the donjon in the castle of Lucera, etc.), later also in Renaissance palaces and villas and in the Baroque.
History
=Classical=
The oculus was used in Ancient Roman architecture, one of the finest examples being that in the dome of the Pantheon, Rome. Open to the weather, it allows rain and air to enter and fall to the floor, where it is carried away through drains. Though the opening looks small, it actually has a diameter of {{convert|8.7|m|ft|abbr=in}}, allowing it to light the building.
=Byzantine=
The oculus was widely used in the architecture of the Byzantine Empire. It was applied to buildings in Syria in the 5th and 6th centuries and again in the 10th century. In Constantinople's Myrelaion Church (c. 920), there are two oculi above the stringcourse on both lateral facades.{{cite book|last1=Ćurčić|first1=Slobodan |last2=Johnson|first2=Mark Joseph |last3=Ousterhout|first3=Robert G. |last4=Papalexandrou|first4=Amy |title=Approaches to Byzantine Architecture and Its Decoration: Studies in Honor of Slobodan Ćurčić |url={{GBurl|id=b5eKujogjYAC|p=148}} |access-date=24 January 2013 |date=1 January 2012 |publisher=Ashgate Publishing |isbn=978-1-4094-2740-7 |pages=148–}}
=Renaissance=
Early examples of the oculus in Renaissance architecture can be seen in Florence Cathedral, in the nave clerestory and topping the crowns of the arcade arches.{{cite web|title=The Cathedral of Santa Maria del Fiore, Florence|url=http://arts.muohio.edu/faculty/benson/florencecathedral/|archive-url=https://web.archive.org/web/20140327234826/http://arts.muohio.edu/faculty/benson/florencecathedral/|url-status=dead|archive-date=March 27, 2014|date=March 27, 2014|access-date= 24 January 2013|website=muohio.edu}}
=Neoclassical=
Since the revival of dome construction beginning in the Italian Renaissance, open oculi have been replaced by light-transmitting cupolas and other round windows, openings, and skylights. They can be seen in the pediments of Palladio's Villa Rotonda, though not in the dome. Use of oculus windows became more popular in Baroque architecture. Widely used by Neo-Palladian architects including Colen Campbell, one can be seen in the dome of Thomas Jefferson's Rotunda at the University of Virginia.{{cite web|url=http://www.arch.virginia.edu/archive/ded7y/vs98/RCstudy1.htm|title=Daylighting in two centroidal spaces at the University of Virginia: Case Study, The Rotunda and Caplin Pavilion|website=The University of Virginia|access-date=24 January 2013|archive-date=28 March 2014|archive-url=https://web.archive.org/web/20140328010912/http://www.arch.virginia.edu/archive/ded7y/vs98/RCstudy1.htm|url-status=dead}}
Examples
{{center|Short visual history of oculli}}
2024 Pantheon Rome 04 2024 7134.jpg|The Ancient Roman oculus (opaion) of the Pantheon, Rome, Italy
Image:Plafond hasht behesht esfahan.jpg|Islamic oculus (opaion) opening into a cupola in the Hasht Behesht, Isfahan, Iran
Oculi - - Altar of Our Lady of Sweat - Duomo - Ravenna 2016.jpg|Baroque oculus (opaion) in a dome of the Ravenna Cathedral, Ravenna, Italy
File:Gassicourt Sainte-Anne 327.JPG|Romanesque oculus of the {{ill|Église Sainte-Anne de Gassicourt|fr}}, Mantes-la-Jolie, France
Cathédrale Notre-Dame de Laon, tour-lanterne 02.jpg|Gothic oculus in the Laon Cathedral, Laon, France
Florence duomo fc10.jpg|Renaissance oculus of the Florence Cathedral, Florence, Italy
Parc de Bagatelle @ Paris (27765814394).jpg|Rococo oculus in the Parc de Bagatelle (Paris)
File:South gate of the Petit Trianon 004.JPG|Louis XVI round window of the Petit Trianon (Versailles, France), with a festoon-derived ornament at the top
Georgsplatz 20, Fensterdetail, Hannover.jpg|Gothic Revival oculus of the Hannoversche Bank - Haus III on Georgstraße, Hannover, Germany
File:Opéra municipal de Clermont-Ferrand, œil de bœuf.jpg|19th century Eclectic Classicist oculus of the {{ill|Opéra-Théâtre de Clermont-Ferrand|fr}}, Clermont-Ferrand, France
File:Fenêtre sur le toit du Palais de Justice.JPG|Beaux-Arts dormer oculus of the Building of Préfecture de Police de Paris, Île de la Cité
Louis Baralis HSBC 1.jpg|Art Nouveau oculus of the {{ill|Hôtel Élysée Palace|fr}}, Paris
La Maison Bleue, porte d'entrée - Angers - 20110119.jpg|Art Deco oculus above a door in Angers, France
References
{{reflist}}
External links
{{Commons category|Oculi}}
{{wiktionary-inline|oculus}}