Kane — The Dun of Drumsna. 327 



bend of the Shannon., opposite Jamestown. 1 The question arises, for what 

 purpose were they constructed ? Now the Dun stretches across a peninsula 

 of comparatively small extent. Unless there had been here at that epoch a 

 bridge spanning the river connecting Roscommon and Lcitrim, there could 

 have been no wheeled traffic in time of peace. Whether a hurdle-ford could 

 have been erected across the Shannon at this place may be doubted, since the 

 width was considerable; and because the name Drumsna is evidence of a well- 

 known swimming-place, it does not seem likely that in early times any better 

 mode of crossing was available. But if for the sake of argument we grant 

 that possibility, one opening would have sufficed. Obviously these two gaps 

 must have been arranged to permit the defending force to deploy at first on 

 the peninsula, and, after contesting the passage of the invaders across the 

 river fords, to provide for their own rapid retreat behind their fortified 

 barriers. But if war chariots were employed, these wide gaps through the 

 more level eastern alignment would have been absolutely necessary. For the 

 precipitous slope of the ground further west would be a natural obstacle for 

 the passage of chariots. Hence none are found there or were required. Both 

 gaps are made defensible by the provision of returns inward of the mound of 

 the great rampart. Each gap is about 50 feet wide, and the flanking returns 

 on both sides of the more easterly one are 47 yards long, and those of the 

 more westerly gap about 63 yards. These side ramparts provide for attacking 

 any entering foe on both flanks. It is to be noted that both of these gaps or 

 passages appear to have been originally metalled with rough field stones, as 

 can be easily discovered by the use of a spade, by removing the sward and 

 accumulated clay for from a foot to eighteen inches. Also opposite and 

 corresponding to the more easterly gap in the great vallum we find similar 

 openings (but without returned ends) left in the outer defensive works, 

 through both that in front and the one in the rear, so providing a complete 

 thoroughfare. 



We cannot doubt that similar openings in the outer defences also existed 

 in the case of the more westerly gap, but there all. these subsidiary earth- 

 works have been levelled. It seems to me also probable that the main central 

 vallum was rendered more impregnable to attack by the use of stockades, and 

 this supposition has been strengthened by the discovery of some decayed 

 remains of the ends of wooden stakes shod with iron points, dug up at the 

 eastern portion of the Doon. These could have served no other purpose. 



The provision of inwardly returned ends of entrances is found both in 

 British and Scottish hill forts, and Mr. Westropp has kindly informed me 



1 See Ground-plan, PL XXIX. 



