Beginning at the north-west corner, I ran my line almost due east to within 10 m.--33 ft.--of the circumvallation, where I found the north-east corner indicated by a broken post of wood. Along this line I met the following sections from west to east: 2.92 m.--9 ft. 6 in.; then a gangway, 1.55 m.--5 ft.; chamber, 3.22 m.--11 ft.; gangway, 1.21 m.--4 ft.; and three chambers, 2.09 m., 2.72 m., and 2.72 m.--7 ft., 9 ft., and 9 ft.--respectively, thus giving, adding to it eight walls of a uniform thickness of 0.33 m.--13 in.,--a total width of 19.07 m.--63 ft. Its length was easily found to be 8.56 m.--28 ft.; the northern appendix, therefore, forming a rectangle of 8.5 m. × 19 m.--28 ft. × 63 ft.,--and containing, as the ground-plan shows, ten rooms and two corridors, the latter running through the structure from north to south. It will also be noticed that the two middle rooms are the largest, measuring each 4.28 m. × 3.22 m.--14 ft. × 10 ft. I must also advert, here, to the fact that this structure is extremely ruined, and that the east part of it exposes the surveyor to dangerous errors. The line _a b_, and its continuation eastwardly to _c_, appears to form the main northern wall of the whole structure. Here the annex, just described, terminates. This wall is of unequal thickness. In the north-westerly projection from _a_ to _b_, a length of 8 m.--26 ft.,--its thickness is 0.63 m.--2 ft.; from _b_ to _c_, on the eastern line, it is only 0.33 m.--13 in.--thick. This inequality indicates also a division of the structure to the southward, as far as the line _d d d_, into two longitudinal sections. The western one, whose four corners are respectively _a_ _b_ _d_ _d_ in the diagram, contains eighteen rooms of equal size, measuring each 3.71 m. × 2.25 m.--12 ft. × 7 ft.; it is consequently, inclusive of the rear wall and the sides, 24.24 m. × 8.08 m.--80 ft. × 27 ft. The eastern division, comprised within the area _b_ _c_ _d_ _d_, has fifteen rooms, or five longitudinal rows of three, whereas the western has six rows of three. The rooms east must therefore be larger than those west, and we see that they measure from east to west respectively, 2.25 m., 2.28 m., and 2.28 m.--7 ft., 7 ft. 6 in., and 7 ft. 6 in.: from north to south, 3.60 m., 5.07 m., 4.43 m., 4.13 m., and 3.43 m.--12 ft., 17 ft., 15 ft., 14 ft., and 11 ft. It is a rectangle, or rather trapezium, 22.31 m. × 7.81 m.--70 ft. × 25 ft.,--consequently the width of the building _B_ is somewhat less on the line _d d d_ than on the line _a b c_. The cause of this singular contraction I have found, and shall afterwards indicate.