window
window.
1. Aperture in a wall to allow light and air to enter a building. If a window-aperture is divided into compartments by means of, say, mullions and transoms, those compartments are lights. In its simplest form, a window is a mere hole in a wall, with an arch or lintel at its head. Some Greek windows on important buildings were narrower at the top than at the bottom (see Tivoli and Vitruvian opening), and had architraves, often with crossettes (see crossette (1) ), as in the Philippeion at Olympia (begun 339 BC).
Roman windows were much larger and more varied in type especially after glazing was readily available by c. AD 65, although other materials were in use until the early C18. Thin parchment stretched on a frame, then painted and varnished; parchment painted and coated with linseed-oil; linen painted and coated with white of egg and gum-water and varnished; paper soaked in poppy-oil, mutton suet, or wax; and linen dipped or coated in beeswax were employed. In many cases glazing was found only in the upper part of the window, the lower part having wooden shutters, and this arrangement was commonly found even in Scotland's Royal palaces until comparatively recently (C18). In Classical architecture, windows not only had architraves, but were crowned with entablatures with or without pediments. In grander window-openings, columns or pilasters may be found on either side supporting an entablature, gable, pediment, etc., in which case they are said to be aediculated (see aedicule).
Early medieval windows were small and narrow, often with splays on cills and reveals of jambs to improve the ingress of light, and this type of construction seems to be of considerable antiquity. It was as much controlled by questions of security as by the problems of keeping rain out. Anglo-Saxon windows were of this type, frequently crudely arched, or with lintels at their heads shaped on the soffits to look like small arched openings, or having two stones set diagonally at the top to form triangular heads: in towers of the period, apertures often consisted of two distinct openings between which were turned baluster-colonnettes with exaggerated entasis. Romanesque windows were larger, but were still of the hole-in-the-wall type, splayed, semicircular-headed, and often decorated with billet or chevron mouldings. Romanesque semicircular-headed lights were occasionally paired, separated by a shaft, and contained within a bigger semicircular-headed opening. Circular window-apertures were common, often in gables, but sometimes elsewhere, e.g. the clerestorey lights of Southwell Minster, Notts. In First Pointed Gothic, early window-apertures were tall and narrow (lancets), almost invariably with splayed jambs, having sharply pointed heads, used singly or sometimes in groups of three or five (as in the eastern gables of chancels (e.g. the Lady Chapel of Hereford Cathedral (c.1220–40)), but circles, quatrefoils, and other simple figures were used, especially in plate-tracery. With the transition to early Middle Pointed came Geometrical bar-tracery and Y-tracery. Second Pointed work introduced Curvilinear, Flowing, Intersecting, and Reticulated tracery, the various lights framed by mullions and bartracery. In England, Perpendicular windows had mullions and transoms subdividing ever-larger windows into panel-like lights, the design often continuing repeated as blind panels over the adjacent walls: the main mullions rose from the cill to the head which, towards the end of the medieval period, was usually a very depressed arch, and transoms were often ornamented with miniature battlements. Tudor Gothic window-heads frequently were four-centred arches, but were also fitted within rectangular apertures subdivided by mullions and framed at the top by a pronounced hood-mould dropping down on either side and terminating in Label-stops. This was the usual arrangement in late-medieval domestic architecture. Elizabethan and Jacobean windows in grander houses were often vast, subdivided by mullions and transoms, called grid-tracery.
2. Filling of a window-opening with glass fixd in a frame or sash of wood or metal, with accessories. The frame usually takes two forms: the casement and the sash. The latter is a frame holding the glass, fixed or opening, set in a large frame encompassing the whole window-opening or aperture: if opening, the operation is effected by a vertical or horizontal sliding movement or by hinges or pivots at the side, top, bottom, or centre. A casement-window, therefore, has a sash or sashes. Sashes moving up and down are called boxed sliding, double-hung, or vertical sliding. In C17, window-frames were often cruciform, with the lights held in frames within each opening, the pieces or quarries of glass secured in lead cames stiffened by saddle-bars fixed to the main frame. One or more of the rectangular sashes were hinged so that they could open in or out, so were referred to as casements.
With the advent of larger panes of crown glass in C17, the design of windows changed, and the sashes were subdivided into rectangular squares or rectangles formed by wooden glazing-bars into which the glass was set. One sash slid vertically in front of the other in grooves formed on robustly constructed frames, and suspended on cords over pulleys, counter-balanced by means of weights free to move up and down inside the boxes within the main frame. This boxed sliding or double-hung sash-window appears to have been an English invention of the 1670s (although some have claimed it originated in The Netherlands), and was employed when earlier windows were replaced in the Palladian Banqueting House, Whitehall, London (1685). From then, double-hung sash-windows gained in popularity, often replacing earlier types. However, the limitations of techniques of manufacturing glass ensured that individual panes remained relatively small, so glazing-bars were universal in better work, and somewhat obtrusive, being thick. During C18, glazing-bars (called astragals in Scotland) were refined and acquired moulded profiles, reducing their visual impact. This elegance of section and improvements in the methods of making glass enabled larger panes to be made, so that in the finest Georgian sliding sash-windows the obtrusiveness of glazing-bars was minimal, and the bars themselves contributed to the overall appearance of refinement and well-proportioned artefacts. During the first decades of C19, proportions of window-openings changed: C18 apertures had generally been tall and narrow, but with the advent of Neo-Classicism and, especially, the Greek Revival, became wider in proportion to height. Extra glazing was introduced at the sides of sashes in narrow strips, often with tinted glass: these were called margin-panes. Continuing improvements of manufacturing techniques made large panes of glass available at reasonable cost from the 1830s, and this again encouraged a change of proportion as windows could become wider still and glazing-bars dispensed with. In many cases glazing-bars were removed from earlier windows, changing the geometry and destroying the vertical emphasis created by repeated vertical rectangular panes. C18 relationships between pane, sash, window, and façade that had been so important in establishing the proportions of Georgian domestic architecture was destroyed. Furthermore, tax changes in England (e.g. repeal of window-tax (1851)) tended to encourage more and larger windows, further freeing design from the earlier constraints. Historically, window-widths were determined by the size and strength of the lintel or the stability of the arch. With the evolution of structural frames, the various changes outlined above, and C19 stylistic eclecticism, traditional relationships of window-openings to solid walls changed. Many contemporary buildings have external cladding (consisting of glass in some kind of light frame as the curtain-wall) forming the enclosing envelope around the internal volumes.
3. Types of window include bay; bow; casement; Catherine-wheel; Chicago; clerestorey; cross; Diocletian or thermal; dormer; fanlight; French (or croisée); Ipswich; laced; lancet; lattice; leper; low-side; lucarne; lychnoscope; marigold; oculus; œil-de-bœuf; oriel; Palladian; picture; rose; sash; serliana; skylight; tracery; Venetian; wheel; Wyatt; and Yorkshire light.
1. Aperture in a wall to allow light and air to enter a building. If a window-aperture is divided into compartments by means of, say, mullions and transoms, those compartments are lights. In its simplest form, a window is a mere hole in a wall, with an arch or lintel at its head. Some Greek windows on important buildings were narrower at the top than at the bottom (see Tivoli and Vitruvian opening), and had architraves, often with crossettes (see crossette (1) ), as in the Philippeion at Olympia (begun 339 BC).
Roman windows were much larger and more varied in type especially after glazing was readily available by c. AD 65, although other materials were in use until the early C18. Thin parchment stretched on a frame, then painted and varnished; parchment painted and coated with linseed-oil; linen painted and coated with white of egg and gum-water and varnished; paper soaked in poppy-oil, mutton suet, or wax; and linen dipped or coated in beeswax were employed. In many cases glazing was found only in the upper part of the window, the lower part having wooden shutters, and this arrangement was commonly found even in Scotland's Royal palaces until comparatively recently (C18). In Classical architecture, windows not only had architraves, but were crowned with entablatures with or without pediments. In grander window-openings, columns or pilasters may be found on either side supporting an entablature, gable, pediment, etc., in which case they are said to be aediculated (see aedicule).
Early medieval windows were small and narrow, often with splays on cills and reveals of jambs to improve the ingress of light, and this type of construction seems to be of considerable antiquity. It was as much controlled by questions of security as by the problems of keeping rain out. Anglo-Saxon windows were of this type, frequently crudely arched, or with lintels at their heads shaped on the soffits to look like small arched openings, or having two stones set diagonally at the top to form triangular heads: in towers of the period, apertures often consisted of two distinct openings between which were turned baluster-colonnettes with exaggerated entasis. Romanesque windows were larger, but were still of the hole-in-the-wall type, splayed, semicircular-headed, and often decorated with billet or chevron mouldings. Romanesque semicircular-headed lights were occasionally paired, separated by a shaft, and contained within a bigger semicircular-headed opening. Circular window-apertures were common, often in gables, but sometimes elsewhere, e.g. the clerestorey lights of Southwell Minster, Notts. In First Pointed Gothic, early window-apertures were tall and narrow (lancets), almost invariably with splayed jambs, having sharply pointed heads, used singly or sometimes in groups of three or five (as in the eastern gables of chancels (e.g. the Lady Chapel of Hereford Cathedral (c.1220–40)), but circles, quatrefoils, and other simple figures were used, especially in plate-tracery. With the transition to early Middle Pointed came Geometrical bar-tracery and Y-tracery. Second Pointed work introduced Curvilinear, Flowing, Intersecting, and Reticulated tracery, the various lights framed by mullions and bartracery. In England, Perpendicular windows had mullions and transoms subdividing ever-larger windows into panel-like lights, the design often continuing repeated as blind panels over the adjacent walls: the main mullions rose from the cill to the head which, towards the end of the medieval period, was usually a very depressed arch, and transoms were often ornamented with miniature battlements. Tudor Gothic window-heads frequently were four-centred arches, but were also fitted within rectangular apertures subdivided by mullions and framed at the top by a pronounced hood-mould dropping down on either side and terminating in Label-stops. This was the usual arrangement in late-medieval domestic architecture. Elizabethan and Jacobean windows in grander houses were often vast, subdivided by mullions and transoms, called grid-tracery.
2. Filling of a window-opening with glass fixd in a frame or sash of wood or metal, with accessories. The frame usually takes two forms: the casement and the sash. The latter is a frame holding the glass, fixed or opening, set in a large frame encompassing the whole window-opening or aperture: if opening, the operation is effected by a vertical or horizontal sliding movement or by hinges or pivots at the side, top, bottom, or centre. A casement-window, therefore, has a sash or sashes. Sashes moving up and down are called boxed sliding, double-hung, or vertical sliding. In C17, window-frames were often cruciform, with the lights held in frames within each opening, the pieces or quarries of glass secured in lead cames stiffened by saddle-bars fixed to the main frame. One or more of the rectangular sashes were hinged so that they could open in or out, so were referred to as casements.
With the advent of larger panes of crown glass in C17, the design of windows changed, and the sashes were subdivided into rectangular squares or rectangles formed by wooden glazing-bars into which the glass was set. One sash slid vertically in front of the other in grooves formed on robustly constructed frames, and suspended on cords over pulleys, counter-balanced by means of weights free to move up and down inside the boxes within the main frame. This boxed sliding or double-hung sash-window appears to have been an English invention of the 1670s (although some have claimed it originated in The Netherlands), and was employed when earlier windows were replaced in the Palladian Banqueting House, Whitehall, London (1685). From then, double-hung sash-windows gained in popularity, often replacing earlier types. However, the limitations of techniques of manufacturing glass ensured that individual panes remained relatively small, so glazing-bars were universal in better work, and somewhat obtrusive, being thick. During C18, glazing-bars (called astragals in Scotland) were refined and acquired moulded profiles, reducing their visual impact. This elegance of section and improvements in the methods of making glass enabled larger panes to be made, so that in the finest Georgian sliding sash-windows the obtrusiveness of glazing-bars was minimal, and the bars themselves contributed to the overall appearance of refinement and well-proportioned artefacts. During the first decades of C19, proportions of window-openings changed: C18 apertures had generally been tall and narrow, but with the advent of Neo-Classicism and, especially, the Greek Revival, became wider in proportion to height. Extra glazing was introduced at the sides of sashes in narrow strips, often with tinted glass: these were called margin-panes. Continuing improvements of manufacturing techniques made large panes of glass available at reasonable cost from the 1830s, and this again encouraged a change of proportion as windows could become wider still and glazing-bars dispensed with. In many cases glazing-bars were removed from earlier windows, changing the geometry and destroying the vertical emphasis created by repeated vertical rectangular panes. C18 relationships between pane, sash, window, and façade that had been so important in establishing the proportions of Georgian domestic architecture was destroyed. Furthermore, tax changes in England (e.g. repeal of window-tax (1851)) tended to encourage more and larger windows, further freeing design from the earlier constraints. Historically, window-widths were determined by the size and strength of the lintel or the stability of the arch. With the evolution of structural frames, the various changes outlined above, and C19 stylistic eclecticism, traditional relationships of window-openings to solid walls changed. Many contemporary buildings have external cladding (consisting of glass in some kind of light frame as the curtain-wall) forming the enclosing envelope around the internal volumes.
3. Types of window include bay; bow; casement; Catherine-wheel; Chicago; clerestorey; cross; Diocletian or thermal; dormer; fanlight; French (or croisée); Ipswich; laced; lancet; lattice; leper; low-side; lucarne; lychnoscope; marigold; oculus; œil-de-bœuf; oriel; Palladian; picture; rose; sash; serliana; skylight; tracery; Venetian; wheel; Wyatt; and Yorkshire light.
Bibliography
AH, xxvi (1983), 49–72;
Gwilt (1903);
Nicholson (1835);
W. Papworth (1892);
J. Parker (1850);
Sturgis et al. (1901–2)
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