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GLOSSARY OF WINDOW AND RELATED TERMS

label, see drip–mould, hood mould [Old French: label, a ribbon or fillet].
Label Stop
label–stop, the termination of a drip–mould or hood–mould, made by cranking the moulding down through ninety degrees and then, for a short length, sideways.
Laced Window
laced windows, the early eighteenth century habit of joining windows set above each other by a material differing from the overall wall surface [Latin: laqueum, a noose].
The Latin origin of ‘lace’, meaning a noose, suggests something more robust than a delicate net, in this case a set of windows ‘hanging together’.
lamb’s tongue, a very slender glazing bar with elongated ogees separated by a narrow fillet, popular in the Regency period.
Lancet Arch
lancet–arch, a two–centred arch with the radii greater than the span.
Lancet Window
lancet window, a tall narrow window, originating in the twelfth century but revived in later periods [French: lance, a spear + diminutive form –ette, small].
The upper termination is always a lancet arch.
Lantern
lantern, lantern–light, a projection above a roof, containing windows.
Lapis Specularis
lapis specularis, a species of translucent stone split into in sheets and used instead of glass in windows [Latin: lapis, stone: specularis, mirror–like].
In this illustration a large frameless window of lapis specularis can be seen from outside and inside. This material, like other stones, can be converted by burning and slaking into plaster, which has been used here to butt–joint the small panes. The traveller Andrew Lumsden tells us in Remarks on the Antiquity of Rome and Its Environs, 1822, that in antiquity ‘glass windows were probably rare; for the ancients, in place of glass, commonly used a transparent stone, lapis specularis, which they called speculum. Pliny informs us, that these stones were first dug in Segobriga in Spain, but that they were afterwards got in Cyprus, in Africa, and in Sicily. It was either talc, or gypsum, or a sort of alabaster . . . It is found in many parts of the world. But the finest and largest sheets hitherto discovered, are on the banks of the river Witim in Siberia. It is called Muscovia talc. The Russians use it in windows in place of glass, and particularly in the windows of their ships; because it is less brittle, and more pliable than glass, and resists better the shock of the rebound of cannon’. Other sources mention five feet as being the maximum size of panel found; it is known that the Romans used such sheets of lapis specularis in greenhouses and cold frames, to grow vegetables. Archaeologists working in Spain have recently concluded from their investigations in the mines there that some of the seams were so small that they can only have been worked by children.
Lattice Window
lattice–window, any hinged or fixed window frame with lozenge–shaped glass panes held together with lead cames [French: lattis, lathwork].
The French meaning indicates the original nature of the lattice–window — simply an unglazed opening with a screen of laths arranged diagonally, or vertically and horizontally. This eventually transmuted itself into the form we also know as leaded lights. Sometimes used a sort of shorthand for casement. This is because earliest windows were metal casements and the earliest glass came in small sizes. Many of the earliest sashes were glazed with lattice pattern lights until glass technology improved.
Leaded Lights
leaded lights, any window that has glass panes held together by lead cames.
In this example the panes are of varying sizes, and are reinforced with saddle–bars, which follow the pattern of the lead cames. Wire ties can be seen at intervals.
leper–window, or leper’s squint, another name for a lychnoscope, or low–side window. See hagioscope.
light, a glass pane in lead cames; or glazing bars in a fixed or hinged frame, forming part of a window.
See also dead–light, margin–light, lattice–window, leaded lights, quarry.
Look Out
look–out, look–out window, an opening or window in a prospect tower or watchtower.
Lintel
lintel, the horizontal member that spans an opening [Old French: lintel, a threshold].
loop, see arrow–loop.
Louvre
louvre, fixed or moveable horizontal laths or boards, fixed above each other and overlapping in such a way as to restrict light entry while allowing ventilation.
Modern louvres may also be of glass. As well as alternative spellings (‘louver’, ‘luffer’) the word has alternative meanings — a smoke outlet on a roof or any structure containing an array of individual louvres (or ‘luffer–boards’). The Oxford English Dictionary says that the ultimate etymology is obscure, but that there can be no connection with the name of the palace of the French kings at Paris, nor with ‘louvre’, a fashionable eighteenth century dance. See also abat–vent.
louvre shutter, a device for shading windows, which may be hinged or sliding.
Continental windows are shaded by jalousies. In Northern climes the louvre shutter predominates; its fixed blades are disposed at an angle that allows moderate shading for most of the day, together with protection from rain. The hinged louvre shutter, when fixed the right way round, performs admirably. But to many people the role of shutters is talismanic and decorative rather than practical. The fact that they may be fixed the wrong way round (letting light in rather than keeping it out), as they frequently are, is of no consequence. It is sufficient that they dress the windows and somehow satisfy some unstated need, untainted by logic or practicality. Are the shutters in the illustration fixed the right way round?
low–side window, see leper–window, lychnoscope.
Lozenge
lozenge, a diamond shaped piece of glass fixed to its neighbour by a lead came. See also leaded lights, quarries.
In the example shown the glass panes have been re–leaded in substantial and possibly original lead cames, while repairs to broken panes have been carried out using cames of a lighter cross–section.
Lozenge Window
lozenge–window, a diamond–shaped window.
Lucarne 1
lucarne (1), a dormer window with its face in the same plane as, or projecting from, the face of the wall.
The latter dormer type has a practical function — that of lifting and lowering goods and materials (often grain) — the floor of the projection being partly removable. In France lucarnes occur in which only a balcony or platform and the roof project beyond the face of the wall, again with an opening in the floor for the same purpose. Variations in spelling are found — lucerne, luthern — as well as corruptions — lucam, lewcome, lookum. The Oxford English Dictionary says that the etymology is obscure and not connected with the Latin lucerna, meaning a lamp, or lamplight.
Lucarne 2
lucarne (2), a small gabled aperture on the slope of a church spire, made of the same material.
lug, see ear.
Lugged Architrave
lugged architrave, an architrave in which the topmost member, acting as a supposed lintel, extends beyond the jambs.
Lunette 1
lunette, a semicircular window [French: lune, moon + diminutive form –ette, small].
lychnoscope, see hagioscope.
Lying Pane Glazing
lying pane glazing, a form of glazing found in traditional sash windows in Scotland, in which the panes lie horizontally within the sash rather than vertically, as is normal elsewhere.
Although the form exists in casement windows and fixed lights outside Scotland this term is never used to identify them. Introduced in the 1930s, horizontal pane steel windows were marketed under the name ‘Homelight’ by Crittall Windows Ltd. and were used in large numbers in modern housing developments throughout Britain. This type of window also occurs in many non–domestic art–deco buildings.