Lancet Arch.—The sharply-pointed window-head and arch, characteristic of English Gothic in the thirteenth century.
Lantern.—A conspicuous feature rising above a roof or crowning a dome, and intended usually to light a Hall, but often introduced simply as an architectural finish to the whole building.
Lierne (rib).—A rib intermediate between the main ribs in Gothic vaulting.
Light.—One of the divisions of a window of which the entire width is divided by one or more mullions.
Lintel.—The stone or beam covering a doorway or other opening not spanned by an arch. Sometimes applied to the architrave of an order.
Loggia (Italian).—An open arcade with a gallery behind.
Loop.—Short for loophole. A very narrow slit in the wall of a fortress, serving as a window, or to shoot through.
Lucarne.—A spire-light. A small window like a slender dormer window.
Moat (or Fosse).—The ditch round a fortress or semi-fortified house.
Mosaic.—An ornament for pavements, walls, and the surfaces of vaults, formed by cementing together small pieces of coloured material (stone, marble, tile, &c.) so as to produce a pattern or picture.