Since the 16th century, Protestant families of glass-making noblemen had settled in the Barade forest and in the Double. These forest glassworks were surrounded by the raw materials needed to make glass: sand for the glass, clay for the furnaces and wood for heating. The soda used as a flux for the glass paste, initially obtained from the ashes of salicornia, has been replaced since the 17th century by potash from the ashes of the royal fern. However, the quality of the glass blown in this way was much poorer. The scarcity of wood and competition from industrial glassworks using charcoal led to the disappearance of the last Perigordine forest glassworks around 1830. At the same time, two industrial glassworks were opened in Brardville and Rottersac, a sign of a new era. Families of Protestant glass-making noblemen from Languedoc, but who did not depart from this "noble art", exploited the sand of the plateaux of the Barade and Double forests from the 16th century to the first decades of the 19th century. This installation of glassworks was favoured by the presence of the raw materials necessary for the manufacture of glass: sand for the glass, clay for the furnaces and wood for heating. Salicornia, a seaside plant and an indispensable ashy ingredient rich in soda used as a fondant mixed with sand, was bought in Bordeaux. It was replaced by the potash contained in the royal fern ash during the troubled period of the Wars of Religion, but the quality of the "verre de fougère" was much lower. This decline in quality and the scarcity of wood, followed by the development of industrial glass factories using charcoal, led to the disappearance of the last forest glass factories in the Périgord around 1830. At the same time, two industrial glassworks were opened in Brardville and Rottersac, a sign of a new era. illustrations : - Photograph of the residence of the Juilhot de la Plante family, master glassworkers at Saint Barthélemy de Bellegarde from the 16th to the 18th c. (© Musée André Voulgre) - Map of the distribution of glassworks in the Isle valley: Installations in Périgord in the Double, the forest of Grandval (part of the Barade forest in the 4 parishes of La Douze, Saint Geyrac, Fossemagne and Bars) to the West and East of Périgueux (and near Biron, towards Mareuil and La Rochebeaucourt.) (© Musée André Voulgre) - Letterhead from the Brardville glass factory around 1900 (Private collection) - Postcard from the Delas glassworks in Brardville at the beginning of the 20th century. (©Archives Départementales de la Dordogne : 2 Fi 1165) - Video Portrait of craftsman The glassblower, by Pascal Magontier, 1980s.
