66 [Proc. B.N.F.C., 



present course of most of our rivers represents only the thread 

 upon which at one time a long chaplet of glittering lakes was 

 strung. Each lake finding its outlet at the point where its 

 confining bank was lowest, and by its cwn action during many 

 centuries cutting back a passage through this barrier until it 

 drained itself, leaving exposed a nearly level plain of alluvium 

 — its former bottom — soon to become covered by vegetation, 

 across which the river now cuts its winding course ; while on 

 some of these holms we can still see, at the point of influx, a 

 portion of the old delta deposited in the lake, showing the 

 height at which its surface remained. Such was the undoubted 

 history of the river holm on which this rath abuts. 



Now, why did the builders of it, who laboriously cut two 

 protecting trenches on the other side, leave this side totally 

 unprotected ? The inference is obvious. This side was then 

 sufficiently protected by the deep water of that ancient lake. 

 The rath, then, is older than the holm, how many centuries 

 older no one now can tell. But how old is the holm ? Let us 

 look around ; if we cannot tell just how old the holm is, we 

 have proof that even it is older than another " unknown 

 quantity," for on its surface still lie the remains of at least one 

 burial tumulus, carrying us back to pre-christian times; and 

 we may fairly assume that hundreds of years had passed over 

 this grassy level before that ancient monument was raised 

 upon it, for no one would have chosen it for such a purpose 

 while even a tradition remained of its having been covered by 

 water. 



The local report about this tumulus, which rests upon the 

 authority of the late Mr. Walsh, the antiquarian of Dromore, 

 is that the stones used in building a portion of the wall round 

 Gilhall demesne were taken out of it. This is probably the 

 truth, for we can see that considerable excavations have been 

 made on two sides of it. Enough still remains, however, to 

 show that it was perfectly circular, with a shallow depression 

 all round. Though composed of stones of moderate size, bound 

 together with earth, it has been so compactly built that during 



