
Hollow bricks in the wall of the caldarium of the Baths’ of the Roman fort Biriciana, Weißenburg (Bavaria/Germany) forming a great flue for the heated air from the fires underneath.
Hollow bricks in the wall of the caldarium of the Baths’ of the Roman fort Biriciana, Weißenburg (Bavaria/Germany) forming a great flue for the heated air from the fires underneath.