11. The spandrels and piers to the wide approach arches are built of coursed rubble masonry . 12. It is constructed of sandstone, rubble masonry , and brick. 13. The church is built of rubble masonry with hamstone dressings, topped by a slate roof. 14. The exposed material is ironstone rubble masonry , with walls. 15. The top-level fortification is constructed in ashlar masonry while the defensive walls are made of rubble masonry . 16. The bridge is built of rubble masonry except for the ledge, which is built of hewn sandstone. 17. The present building is rectangular, using rubble masonry dressed with freestone; the roof uses slates and stone copings. 18. The winding house includes two lateral walls of mortared walls of rubble masonry supporting a square drive shaft and bearings. 19. The wall was constructed of rubble masonry in a total amount of 248480 cubic meters ( 325, 000 cubic yards ). 20. Most of the buildings in the epicentral area were constructed of thick walls made from rubble masonry cemented with mud mortar.
