Essay on Caerphilly Castle. 103 



The neiglibouriug brooks would amply supply the inhabitants with water, 

 the morass was a sufficient safeguard against their enemies^ and the sur- 

 rounding plains would affijrd food for themselves and pasture for their 

 cattle — if they had any. 



When, however, the more civilized Normans obtained possession of this 

 spot, and laid the foundation of the present extended structure, the sur- 

 face of the ground seems to have undergone very considerable alteration. 

 The bed of the Nant-y-Gledyr having been dammed up at its gorge, be- 

 yond the termination of the peninsula, the whole southern swamp became 

 at once an extensive sheet of water. The dam, of masonry, in the form of 

 a strong and lofty wall, was carried along in a northerly direction, until it 

 terminated in the bank that has been described as curling round from the 

 north, and thus cutting off also the exit of the smaller brook, the whole 

 horse-shoe-shaped bottom was converted into a continuous lake. 



The dam of the Nant-y-Gledyr was furnished with sluices to regulate 

 the height of the inundation ; and similar appendages were added on the 

 north, whence, by means of an artificial channel, to the west of the natural 

 one, the waste waters on that side found a way to their ultimate destina- 

 tion. This channel we shall call the " North-brook," and the neighbouring 

 rivulet the " Farm-brook.'' 



Advantage was taken of a narrow slightly lunated ridge, which proceed- 

 ing from the root of the peninsula, traversed the northern swamp nearly 

 parallel to the tongue of land, dividing it into two portions, a smaller 

 forming the inner, and a larger the middle moat ; the outer having been 

 already described as the channel of the north brook. 



By this ridge all connexion between the nortliern part of the northern, 

 and the southern inundation was cut off; with the latter, however, the inner 

 moat still communicated, on the eastern side passing round the peninsula, 

 and on the western through the old transverse cut, now widened and 

 deepened. 



Tlie island thus completely formed, was scarped into curtains and bas- 

 tions, and faced or revetted with stone ; and the single transverse cut not 

 being deemed a sufficient defence, the peninsula was a second time divided 

 further to westward ; and the second island thus formed turned into a sort 

 of hornwork, or demi-lune. 



To recapitulate. We have centrally the apex of the peninsula converted 

 into an island, and protected on two sides by the southern lake and its 

 eastern prolongation j on the north, by the inner division of the northern 

 swamp J and on the west, by the transverse fissure ; all uniting to form 

 one moat. 



Proceeding outwardly we have next, as the boundaries of this moat, on 

 tiic west, the second island or hornwork, ])rolonged on the north into the 

 lunated ridge ; on the east, the natural bank and the dam of the Nant-y- 

 Glcdyr; on the south, the acclivity of the bank, rising rather steeply from 



