Rozmach sklářské výroby za římského císařství. (Foukané sklo ze sbírky Národního muzea) / Flourishing Period of Glassmaking during the Roman Imperial Age (the Blown Glass from the Collection in the Prague National Museum)
The discovery that glass can be expanded by human breath altered the history of glass-making. Tube blowing was the first step in this process. Invention of the blow pipe and using of pontil rod were technical improvements which soon followed. Collection of the National Museum contains undecorated vessels such as urns, unguent and square bottles and glass decorated by trailed patterns, engraving and cutting. Most vessels are found at the eastern and western parts of Roman Empire as well, sprinkler with globural body and cosmetic vessel with double tubes are products of the eastern Mediterranean industry.