On either side of this are octagonal turrets with cupolas and delicately pierced parapets. The colonnades, arches, balustrades and cupolas are of typically intricate Victorian style. The style became more decorated and ornamental, statuary, domes and cupolas becoming very evident. The roof was tiled in terracotta shingles from Marseilles surmounted by copper-domed cupolas. Italianate elements emerged in the 1840s including cupolas, verandas, ornamental brickwork, or corner quoins. The cathedral has ten towers with gilded cupolas. Floors Castle was transformed in 1838 by William Playfair who added grand turrets and cupolas. Modern furnace types include electric arc furnaces (EAF), induction furnaces, cupolas, reverberatory, and crucible furnaces. The passages along the courtyard have vaulted ceilings, cupolas and intricate corridors. For ferrous materials EAFs, cupolas, and induction furnaces are commonly used. It is approximately rectangular in shape with canted corners that are topped with stone cupolas. In basic refractory lined cupolas the slag is brown. Each position was surrounded by several ditches, with shelters and observation cupolas. Some were also retro-fitted with commander's cupolas. They were able to use the hollow charges to destroy or disable the gun cupolas.