The oldest finds of artificially produced glass in the form of glass beads date back to around 3500 BC from Egyptian royal tombs. Around 1500 BC, the first hollow glasses were produced in Egypt and in the Mesopotamian region and wine glasses were already being used. At that time, the glass was heated to about 900 °C, it was then in a viscous state and was wrapped around solid sand or clay cores and modelled. Its fragility prevented glass from being used for larger containers and thus for transport. Around 200 BC, the invention of the glassmaker's pipe (glass blowing) and the glass melting furnace by the Phoenicians in what is now Syria fundamentally revolutionised glass production.