View source for Engineering:Transom (architectural)

[[Image:DoorEsplanadeDec071260.jpg|thumb|A transom and transom light over double doors]]
In architecture, a '''transom''' is a transverse horizontal structural beam or bar, or a crosspiece separating a door from a window above it. This contrasts with a [[Engineering:Mullion|mullion]], a ''vertical'' structural member.<ref name="efficient">{{cite web |url=http://www.efficientwindows.org/glossary.cfm#t |title=The Efficient Windows Collaborative: Glossary |accessdate=2007-12-13 |deadurl=no |archiveurl=https://web.archive.org/web/20071128060303/http://www.efficientwindows.org/glossary.cfm#t |archivedate=2007-11-28 |df= }}</ref> Transom or '''transom window''' is also the customary U.S. word used for a '''transom light''', the window over this crosspiece.<ref name="efficient"/><ref name=bigblue>{{cite web |url=http://www.bigbluewindow.com/faq.aspx#q50 |title=What is a transom window? |publisher=Big Blue Window |accessdate=2007-12-13 |deadurl=no |archiveurl=https://web.archive.org/web/20071228022533/http://www.bigbluewindow.com/faq.aspx#q50 |archivedate=2007-12-28 |df= }}</ref> In Britain, the transom light is usually referred to as a ''fanlight'', often with a semi-circular shape, especially when the window is segmented like the slats of a folding [[Physics:Hand fan|hand fan]]. A well-known example of this is at the main entrance of 10 Downing Street, London.<ref>{{cite web |url=https://upload.wikimedia.org/wikipedia/commons/thumb/1/13/10_Downing_Street._MOD_45155532.jpg/1920px-10_Downing_Street._MOD_45155532.jpg |title=Archived copy |accessdate=2016-05-30 |deadurl=no |archiveurl=https://web.archive.org/web/20160820192828/https://upload.wikimedia.org/wikipedia/commons/thumb/1/13/10_Downing_Street._MOD_45155532.jpg/1920px-10_Downing_Street._MOD_45155532.jpg |archivedate=2016-08-20 |df= }}</ref>

==History==
In early Gothic [[Engineering:Church (building)|ecclesiastical]] work, transoms are found only in [[Engineering:Belfry (architecture)|belfry]] unglazed windows or [[Engineering:Spire|spire]] lights, where they were deemed necessary to strengthen the [[Engineering:Mullion|mullion]]s in the absence of the [[Chemistry:Iron|iron]] stay bars, which in glazed windows served a similar purpose. In the later Gothic, and more especially the Perpendicular Period, the introduction of transoms became common in windows of all kinds.<ref name=gothic>{{cite web |url=http://infomotions.com/etexts/gutenberg/dirs/1/9/7/3/19737/19737.htm |title=The Principles of Gothic Ecclesiastical Architecture, Elucidated by Question and Answer, 4th ed. |publisher=Project Gutenberg |accessdate=2007-12-13 |deadurl=yes |archiveurl=https://web.archive.org/web/20110625135303/http://infomotions.com/etexts/gutenberg/dirs/1/9/7/3/19737/19737.htm |archivedate=2011-06-25 |df= }}</ref>

==Function==

Transom windows which could be opened to provide cross-ventilation while maintaining security and privacy (due to their small size and height above floor level) were a common feature of office buildings and apartments before air conditioning became common.<ref>Fred. T. Hodgson, "Ventilation of Middle-Class Dwellings", ''Popular Science News'' August 1902, [https://books.google.com/books?id=fWLnAAAAMAAJ&pg=PA185 p. 185]</ref><ref>"Going 'over the transom': Interior Windows and the Hardware that Moves them", ''Old-House Journal'' January-February 1996, p. 52</ref>

In order to operate opening transom windows, they were generally fitted with ''transom operators'', a sort of wand assembly.<ref>Brian D. Coleman, "Window Hardware 101" ''Old House Interiors'' July-August 2010, p. 29</ref> In industrial buildings, transom operators could use a variety of mechanical arrangements.<ref>Lord & Burnham Company, Manufacturers of Sash Operating Apparatus for Hinged and Pivoted Sash, in ''Chemical Engineering Catalog'', 1919, [https://books.google.com/books?id=uxETAQAAMAAJ&pg=PA706 p. 706]</ref>

==Idiomatic usage==
The phrase "over the transom" refers to works submitted for publication without being solicited. The image evoked is of a writer tossing a manuscript through the open window over the door of the publisher's office.<ref name=freelance>{{cite web |url=http://www.aboutfreelancewriting.com/articles/gettingstarted/QAoverthetransom.htm |title=What Does Over The Transom Mean? |publisher=About Freelance Writing |accessdate=2007-12-13 |deadurl=no |archiveurl=https://web.archive.org/web/20071213192844/http://www.aboutfreelancewriting.com/articles/gettingstarted/QAoverthetransom.htm |archivedate=2007-12-13 |df= }}</ref> 

Similarly, the phrase is used to describe the means by which confidential documents, information or tips were delivered anonymously to someone who is not officially supposed to have them.<ref>Hartocollis, Anemona. [https://www.nytimes.com/2007/11/16/nyregion/16indict.html?ex=1353301200&en=7eea0ce14dac4703&ei=5124&partner=permalink&exprod=permalink Former G.O.P. Official Admits He Evaded Taxes] {{webarchive|url=https://web.archive.org/web/20171105234045/http://www.nytimes.com/2007/11/16/nyregion/16indict.html?ex=1353301200&en=7eea0ce14dac4703&ei=5124&partner=permalink&exprod=permalink |date=2017-11-05 }}, ''The New York Times'', 16 November 2007. DA Morganthau Cites "Over the Transom" Letter as root of fraud investigation</ref>

[[File:Kochi Castle 05.JPG|right|thumb|A ''ranma'' found in Kōchi Castle designed to look like a wave.]]

"Like pushing a piano through a transom" is a folk idiom used to describe something exceedingly difficult; its application to childbirth (and possibly its origin) has been attributed to Alice Roosevelt Longworth and Fannie Brice.

==Japan==
Architectural details called {{nihongo|''ranma''|欄間|}} are often found above doors in traditional Japanese houses and buildings. 

These details can be anything from simple shōji-style dividers to elaborate wooden carvings.and they serve as a traditional welcome to visitors of the head of the household.

==See also==

* Fanlight, a semicircular or semi-elliptical transom window
* [[Engineering:Roof lantern|Roof lantern]]
* [[Engineering:Sidelight|Sidelight]]
* [[Earth:Daylighting#Skylights|Skylight]]
* [[Engineering:Fortochka|Fortochka]]

== References ==

{{reflist}}

[[Category:Architectural elements]]

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