Editing Window (section)

=== Technologies ===
In the 13th century BC, the earliest windows were unglazed openings in a roof to admit light during the day.{{citation needed|date=January 2023}} Later,{{when|date=October 2016}} windows were covered with animal hide, cloth, or wood. [[Window shutter|Shutters]] that could be opened and closed came next.{{when|date=October 2016}} Over time, windows were built that both protected the inhabitants from the elements and transmitted light, using multiple small pieces of translucent material, such as flattened pieces of translucent animal horn, paper sheets, thin slices of [[marble]] (such as [[fengite]]), or pieces of glass, set in frameworks of wood, iron or lead. In the Far East, paper was used to fill windows.<ref name="britannica.com">{{cite encyclopedia| url= http://www.britannica.com/EBchecked/topic/645175/window |title=Window
|encyclopedia= Britannica|access-date=May 19, 2012}}</ref>
The Romans were the first known users of glass for windows, exploiting a technology likely first developed in [[Roman Egypt]]. Specifically, in [[Alexandria]] {{circa}} 100 CE, [[Glass casting|cast-glass]] windows, albeit with poor optical properties, began to appear, but these were small thick productions, little more than [[glass blowing|blown-glass]] jars (cylindrical shapes) flattened out into sheets with circular striation patterns throughout. (Compare traditional [[church window]]s made of [[stained glass]].) It would be over a millennium before window glass became transparent enough to see through clearly, as we expect now. (However, ancient Roman windows were still very useful, as they presented "an often-overlooked advance in heating technology (allowing solar heat to enter a home or building while preventing the warmed air from escaping)."<ref>{{cite book |last1=Carrier |first1=Richard |title=The Scientist in the Early Roman Empire |date=2017 |publisher=Pitchstone Publishing |location=Durham, North Carolina |isbn=978-1-63431-106-9 |page=218}}</ref>) In 1154, [[Muhammad al-Idrisi|Al-Idrisi]] described glass windows as a feature of the palace belonging to the king of the [[Ghana Empire]].<ref>{{cite book | url= https://books.google.com/books?id=umyHqvAErOAC&dq=Ghana+Empire+glass+window&pg=PA564 | title= Encyclopedia of African History 3-Volume Set| page= 564|author= Kevin Shillington |author-link= Kevin Shillington| publisher= [[Routledge]] | isbn= 978-1-135-45670-2 |date= 2013}}</ref><ref>{{cite journal | last= Fage | first=J. D. | title=Ancient Ghana: A Review Of The Evidence | journal=Transactions of the Historical Society of Ghana | volume= 3 | issue= 2 | pages= 3–24 | year= 1957| jstor= 41405704}}</ref>

Over the centuries techniques were developed to shear through one side of a blown glass [[Cylinder (geometry)|cylinder]] and produce thinner rectangular window panes from the same amount of glass material. This gave rise to tall narrow windows, usually separated by a vertical support called a [[mullion]]. Mullioned glass windows were the windows of choice{{when|date=January 2023}} among the European well-to-do, whereas paper windows were economical and widely used in ancient China, Korea, and Japan. In England, glass became common in the windows of ordinary homes only in the early 17th century, whereas windows made up of panes of flattened animal horn were used as early as the 14th century.<ref>{{cite book|last=Langley|first=Andrew|title=Medieval Life|series= Eyewitness|year= 2011 |publisher= Dorling Kindersley|isbn=978-1-4053-4545-3|page=16}}</ref>

Modern-style floor-to-ceiling windows became possible only after the industrial [[plate glass|plate]] [[Glass production|glass-making]] processes were perfected in the late 19th century.<ref>{{cite web|title=Float Glass|url=https://www.architectmagazine.com/technology/float-glass_o}}</ref> Modern windows are usually filled using glass, although transparent plastic is also used.<ref name="britannica.com" />