Glassmaking began in the German city of Ilmenau in 1852.  In 1872, the firm Alt, Eberhardt & Jaeger (qv) was founded to make thermometers and other glass instruments.  In 1969 mergers led to the formation of Technical Glass Ilmenau, which became Ilmenau Glass Works in 1990 with the end of state control.  They went out of business in 2014.