400When this work [for the foundation] was done in this manner, and joined together as part of the hill itself to the very top of it, he wrought it all into one outward surface, and filled up the hollow places which were about the wall, and made it a level on the external upper surface, and a smooth level also. This hill was walled all round, and in compass four furlongs, [the distance of] each angle containing in length a furlong: