Architectural glass is glass that is used as a building material. It is most typically used as transparent glazing material in the building envelope, including windows in the external walls. Glass is also used for internal partitions and as an architectural feature. When used in buildings, glass is often of a safety type, which include reinforced, toughened and laminated glasses. History Timeline of modern architectural glass development 1226: "Broad Sheet" first produced in Sussex. 1330: "Crown glass" for art work and vessels first produced in Rouen, France. "Broad Sheet" also produced. Both were also supplied for export. 1500s: A method of making mirrors out of plate glass was developed by Venetian glassmakers on the island of Murano, who covered the back of the glass with a mercury-tin amalgam, obtaining near-perfect and undistorted reflection. 1620s: "Blown plate" first produced in London. Used for mirrors and coach plates. 1678: "Crown glass" first produced in London. This process dominated until the 19th century. 1843: An early form of "float glass" invented by Henry Bessemer, pouring glass onto liquid tin. Expensive and not a commercial success. 1874: Tempered glass is developed by Francois Barthelemy Alfred Royer de la Bastie (1830–1901) of Paris, France, by quenching almost molten glass in a heated bath of oil or grease. 1888: Machine-rolled glass introduced, allowing patterns. 1898: Wired-cast glass first commercially produced by Pilkington for use where safety or security was an issue. 1959: Float glass launched in UK. Invented by Sir Alastair Pilkington. Cast glass Glass casting is the process in which glass objects are cast by directing molten glass into a mould where it solidifies. The technique has been used since the Egyptian period. Modern cast glass is formed by a variety of processes such as kiln casting, or casting into sand, graphite or metal moulds. Cast glass windows, albeit with poor optical qualities, began to appear in the most important buildings in Rome and the most luxurious villas of Herculaneum and Pompeii. Crown glass One of the earliest methods of glass window manufacture was the crown glass method. Hot blown glass was cut open opposite the pipe, then rapidly spun on a table before it could cool. Centrifugal force shaped the hot globe of glass into a round, flat sheet. The sheet would then be broken off the pipe and trimmed to form a rectangular window to fit into a frame. At the center of