Adolphe Braun, 1870-1871, Belfort le Château, vue prise du Glacis. [the castle at Belfort, seen from the glacis], [Théâtre de la Guerre, 1870-1871], Albumen print, Paul Frecker, LL/17195
Adolphe Braun 1870-1871 Belfort le Château, vue prise du Glacis. [the castle at Belfort, seen from the glacis] [Théâtre de la Guerre, 1870-1871]
A glacis in military engineering is an artificial slope of earth in front of works such as fortifications, so constructed as to keep any potential assailant under the fire of the defenders to the last possible moment.