Dioelling Places of Prehistoric Man 55 



enclosed rampart, so much so that if we take a trench say lo feet 

 wide and 5 feet det-p, with an outside diametrical measurement of 

 say 100 feet, the excavated soil will build a rampart inside, of a 

 height of 8 feet of an outside diametrical measurement of 80 feet. 

 Thus from the bottom of the original trench 5 feet deep to the top 

 of the enclosed rampart, the height would be 13 feet. These 

 measurements are only applicable to the smaller and less important 

 examples. When we come to examples like Dungall or Lisnalinchy 

 where the trench was made deeper the ocular deception is more in 

 evidence. In Dungall, the trench was originally probably 20 feet 

 deep and 35 feet wide. The excavated soil thrown up to make a 

 rampart rose to about 30 feet high in the smaller circumference, so 

 that the actual height from the bottom of the trench to the top of 

 the rampart is about 50 feet. In nearly all cases the trenches have 

 been the receptacles of weeds and general farm rubbish where the 

 surrounding lands have been tilled, so that hardly any of them are 

 now as deep as they originally were ; in some cases the trench has 

 been filled in altogether. But an important fact is nearly always 

 overlooked ; this is that, as a general rule, the central floor of an 

 ordinary rath is virgin soil. Very often the trench and ram- 

 part were thrown up round a raised natural hillock, but the fact 

 remains that the central floor of a ring fort is seldom of piled-up 

 soil. In all instances where a souterrain is found in the centre of 

 a fort, it has been built in virgin boulder clay and is perfectly 

 independent of the earth works thrown up round it. In the fort 

 of Ballyedward, next townland to Ballyrickardmore, the natural 

 site of the fort was a fairly steep hillock. A natural spring rises on 

 the flat top, and some distance from this is the souterrain. When 

 the place was chosen as a fort site the usual surrounding trench 

 was dug, the excavated soil being thrown up to make a rampart. 

 The result of this was that the natural outflow from the spring 

 was stopped up and it found its way into the souterrain, from 

 whence it trickles out through a soft place in the rampart into 

 the encircling trench. This, I think, we may take as a positive 

 proof that the souterrain was there long before the erection of the 

 ramparts which diverted the water of the spring into it. Again in 



