328 Proceedings of the Royal Irish Academy. 



that at Castle O'er, Dumfriesshire, they appear both inside and outside of 

 the principal vallum, and at Chester Bigs Fort in Peebles a good example 

 returned inwards occurs. A remarkable one is found also at Pen-y-Corddyn, 

 near Abergele, but he cannot cite any examples of the kind in the gaps of 

 Irish promontory forts. These defensible entrances into hill forts are, of 

 course, narrow, 6 feet to 10 feet wide, but the gaps through the linear entrench- 

 ments at Drumsna are nearly 50 feet wide, which is inexplicable to me, 

 except on the hypothesis above suggested. They appear to be part and parcel 

 of the original construction of the vallum, and are for the most part evenly 

 tapered. Had they been modern breaches for the passage of a cart, a width 

 of 12 feet would have been ample, and the material would have been disposed 

 on both sides of the vallum to save labour. But the returns are only inward, 

 and are about three times as long as the width of the gap, requiring much 

 additional material to the amount provided by the mere excavation of the 

 opening through the vallum. Moreover, the existence of two, both approxi- 

 mately of similar size and construction, indicates a plan not likely to have 

 been followed in a work of demolition for farm requirements. 1 



I am indebted to the Eight Hon. Michael P. Cox, whose family lived in 

 the neighbourhood, for information that some wooden frame-work has been 

 dug up, apparently the relics of shelters or sentry-boxes. I have recorded in 

 a former paper that oaken beams and frame-work of the sides and flooring of 

 sheds were similarly dug up out of trenches on the defensive side of the 

 rampart of the Black Pig in the Co. of Monaghan. 



During the war that followed upon the insurrection of 1641 down to 1652, 

 Jamestown was captured by Sarsfield for the King, and a Parliamentary 

 army is said to have encamped hereabouts and cannonaded its walls from the 

 height of Ardanaffrin.- I have also been told of guns and other weapons 

 having been found in the neighbourhood of the Dun, referable perhaps to 

 this period. 



I shall now revert to the plan of the works at the eastern end. Here I 

 have pointed out that a fosse, bordered by two banks of no great size, runs 

 close along the foot of the great vallum on its northern face, divided from it 

 by a stoned causeway of about 12 feet wide, but increasing to 30 feet wide 

 further west. This line of frontal defences persists throughout the length of 



1 I have consulted several publications descriptive of the Wansdyke, an early frontier 

 fortification, whose earthworks extend from Somerset to Berkshire. The charts and 

 maps show a few thoroughfares that were left in the vallum. None of them, however, 

 have any defensive returns similar to those of the Drumsna Dun, but there are always 

 camps constructed alongside. 



- Cf. " The Battle of the Boyne " (Boulger), p. 127. 



