Bontemps on Glass Making

Bontemps on Glass Making: the Guide du Verrier of Georges Bontemps
The fifth in a series on how the understanding of glassmaking advanced over the course of three centuries from the early 1600s to around 1870.
Georges Bontemps (1799-1884) was probably the most skilful and adventurous European glass works manager of his age. His life began inauspiciously because he was illegitimate and ignored by his father, a graduate of the École polytechnique and army officer. In 1817 Georges was refused entry to the École polytechnique, despite having done well in the entry examination.
Bontemp then became assistant to Dartigues, owner of three separate works making lead crystal, and was soon managing the glass making at Baccarat. By 1822 he was directing the glass works at Choisy-le-Roi which was unusual in making several kinds of glass including window glass, lead crystal, domestic wares such as drinking glasses, stained glass windows, and optical glass. At Choisy-le-Roi he was responsible for several major advances. He remained there until 1848 when he moved to England to work for Chance Brothers in Smethwick for six years before returning to France.
His Guide du Verrier, published in 1868, is the most detailed known authoritative description of the glass making practices of his time. Its seven sections describe the techniques of glass melting and making window glass, plate glass, bottles, lead crystal, optical glass, and stained glass windows. Bontemps had firsthand experience of all of these except making cast plate. Dozens of batch recipes are given, especially of coloured glasses. The book is copiously illustrated. One of its unique features is an analysis of the economics of the process at the end of each section.