History of glass
Glass remained a luxury material, and the disasters that overtook Late Bronze Age civilizations seem to have brought glass-making to a halt. It picked up again in its former sites, Syria and Cyprus, in the 9th century BC, when the techniques for making colorless glass were discovered. The first glassmaking "manual" dates back to ca. 650 BC. Instructions on how to make glass are contained in cuneiform tablets discovered in the library of the Assyrian king Ashurbanipal. In Egypt glass-making did not revive until it was reintroduced in Ptolemaic Alexandria. Core-formed vessels and beads were still widely produced, but other techniques came to the fore with experimentation and technological advancements. During the Hellenistic period many new techniques of glass production were introduced and glass began to be used to make larger pieces, notably table wares. Techniques developed during this period include 'slumping' viscous (but not fully molten) glass over a mould in order to form a dish and 'millefiori' (meaning 'thousand flowers') technique, where canes of multicolored glass were sliced and the slices arranged together and fused in a mould to create a mosaic-like effect. It was also during this period that colorless or decolored glass began to be prized and methods for achieving this effect were investigated more fully.
Skylight
Prior to the Industrial Revolution, it was France that probably had the leading technology in architectural glass. One of the earliest forms of the glass skylight can be seen at the Palace of Versailles in the Galerie des Batailles, which was added onto the existing palace by Louis Philippe in the year 1830. Another form that displays early sky lighting technology is the Halle aux blés (Paris) built in 1763-67. This form of natural overhead lighting allowed for illumination while decoration could cover the entire interior wall, and it is the option least obstructed by other buildings. This means that sky lighting as we know it, in many forms today, was probably pioneered in France during the early 18th century or late 17th century. According to architectural glass, the earliest functional skylights would have been formed by either glass casting, crown glass (window), cylinder blown sheet, and machine drawn cylinder sheet, or fourcault process.