with walls of Roman towns, on the Rhine. They are to be seen, for instance, at the Saalburg,[1] at Böckingen,[2] and at Trier,[3] as well as in many other places. Of the wide rampart lying at the back of the wall we have the remains at Gellygaer in Glamorgan,[4] where the steps placed at the side of the gate towers to give access to the platform were also found. The height to which the walls were carried no doubt varied very considerably in different places. Here, as in every other detail of Roman fortification, the conditions of the site, the presence of material, the danger of attack must all have counted for much. At Caerleon on Usk the wall at the southern angle still stands some fifteen feet high.[5] At Holzhausen the remains are considerable, and it has been calculated that the total height with breastwork and battlements was fifteen feet.[6] In some cases it must have been greater. The late fort of Dâ Gânîya on the Eastern Limes on the borders of Arabia was defended by a wall of seven feet two inches thick with fourteen towers. In 1888 it was still standing in places nearly thirty feet high. The battlements had, however, disappeared.[7]

Of the towers which were not infrequently set on the walls of forts, we have no trace at Newstead except at the gateways. At Castlecary at least two of the angles were probably equipped with this extra defence. Several towers had stood on the walls both at Gellygaer and at Housesteads,[8] while at Wiesbaden there were no less than twenty-eight.[9] On the other hand, at the Saalburg, at Zugmantel, and at Holzhausen; the towers were only on the gates, a position in which we almost invariably find them in the stone-walled forts. It is quite possible that the Newstead gate towers may have risen some little height above the platform of the wall, for in the forts of the Eastern Limes the towers on the walls were of more than one story,[10] while at Pompeii they had three floors, and reached a height of about forty-five feet.[11]

1 Jacobi, Das Römerkastell Saalburg, p. 69.

2 Der Obergermanisch-Raetische Limes, Lief. 10, Kastell Bockingen, Taf. iii fig. 25.

3 Westdeutsche Zeitschrift, vol. xv p. 222.

4 Ward, The Roman Fort of Gellygaer, p. 39.

5 Liverpool Committee for Excavations, etc., in Wales and the Marches, First Annual Report, p. 56.

6 Der Obergermanisch-Raetische Limes, Lief. 22, Kastell Holzhausen.

7 Brunnow and Domaszewski, Die Provincia Arabia, vol. ii. p. 8, Taf. xli.

8 Archaeologia Aeliana, vol, xxv p. 245.

9 Der Obergermanisch-Raetische Limes, Lief. 31, Kastell Wiesbaden.

10 Brunnow and Domaszewski, Die Provincia Arabia, vol. i. Odruh, p. 431, Taf. xxii.

11 Rochas d'Aiglun, Principes de la fortification antique, p. 89.