Eventually, the dominance of "cristallo" came to an end. In 1673, English glass merchant George Ravenscroft created a clear glass he called "crystalline"—but it was not stable. Three years later, he improved this glass by adding lead oxide, and lead glass (a.k.a. crystal) was created. Ravenscroft, who had lived for many years in Venice, made lead crystal that was less breakable than "cristallo". In 1674, Bohemian glassmaker Louis Le Vasseur made crystal that was similar to Ravenscroft's. In 1678, Johan Friedrich Kunkel von Lowenstein produced a "cristallo"-like glass in Potsdam. The Bohemian and Prussian-style glass was later modified by the addition of lime and chalk. This new glass is attributed to Bohemian glassmaker Michael Müller in 1683. The Bohemian glass was not suitable to the Murano-style artwork on the glass. However, this harder glass was produced as a thicker glass suitable for engraving and grinding. The Bohemian and English glass eventually became more popular than "cristallo" made in Murano. By the 1700s, Murano glass was traded mostly with Italian states and the Turkish empire. Small quantities were traded with England, Flanders, the Netherlands and Spain.