ROMAN FORTIFICATION. 141 



wall threatened by the enemy. There must have been a second 

 wall some 15 to 25 feet from this one, for the Romans, if they had 

 found the chalk so solid as to be a sufficient protection against the 

 ram without the support of a stone wall, could not if we can trust 

 Vitruvius and Vegetius have given the enemy the protection of 

 the ditch and the advantage of the high ground of the rampart in 

 making an assault, it was so distinctly opposed to their general 

 practice. This shows the importance of making further excavations, 

 and the spot which appears to ofler the best results is by the West 

 Walk Cottages. A trench cut across the rampart here should 

 reveal its construction and lay bare the foundations of both walls, 

 unless they have been completely removed, as they have been in the 

 South Walk ; but from the form of the rampart here it does not 

 seem likely that every trace of the walls has disappeared. 



Yitruvius gives the rule for the thickness of walls. They should 

 be sufficiently thick " for two armed to pass each other with ease." 

 The old walls of Dorchester are stated by Stukeley to have been 

 twelve feet in width ; allowing for the parapet and battlements, 

 there would be left ample room for two armed men to pass each 

 other. I would just add here that it is not clear from Dr. Stukeley's 

 description whether he is speaking of the wall or of its foundation ; 

 if the latter, the wall may have been nine or ten feet in thickness. 

 As to the original height of the wall, the height to the top of the 

 portion now standing is about eleven feet above the paved way. 

 Stukeley says : " I saw the foundation of it (i.e., the wall) in a 

 sawpit laid upon solid chalk. It is yet twelve feet high," which 

 suggests that there were indications that it had been higher. 

 Suppose it to have been sixteen feet originally, add 4*6 for the 

 parapet and battlements, and you have a total height of over 20 feet, 

 and this, remember, for the inner wall, if it toas the inner wall, 

 which was generally lower than the outer one and less strong. 



The directions of Yitruvius for building town walls include the 

 construction of towers. " Moreover/' he says, " turrets must be 

 projected outwardly, so that when the enemy wishes to storm the 

 wall he may be wounded with missiles on his exposed side from the 



