Western elevation: north at bottom of picture.  The furnace is at the north ends of the structure.  Gas and dust from the furnace were fed into the western chamber and then into the east; these were for collecting the dust rather than to allow gasses to crystallise as normal in a Brunton calciner.  The wall separating the chambers has holes to allow easy movement of particles.  Because the process used heavy cast-iron rabble arms for raking ore it produced more dust than other processes.