190 Essay on Caerphilly Castle. 



never passing diagonalJy from an angle towards the centre, in the manner 

 employed at Portchester and elsewhere, to vault a compartment of such 

 passages. 



There appear to have been more than one kind of pont levis, or draw- 

 bridge, emi>loyed in this castle. In some places, as at the great gate, and 

 at the passage in its gate-house tower, the bridge, when drawn up, fitted into 

 a depression, so as to lie flush with the upper wall, from whence, therefore, 

 its length may be known. In other cases it simply rested against the wall, 

 making a projection. It seems alvvajs to have been long enough, when up, 

 to cover the gateway. 



The method of hinging the bridge also varied. On the sides of some of 

 the portals, a stone has been inserted, into which the horizontal pivots of 

 the bridge (of iron, from the small size of tlie groove) fitted ; but connected 

 with the place for the pivot is another groove, which passes up at an angle 

 of 45°, for a few feet, and then passes on horizontally for a few more. It 

 appears as though this were a contrivance when the bridge was raised, for 

 throwing its lower end upwards and forwards, so as more efiectually to 

 shield the upper part of the door, to present an oblique surface to missiles, 

 and by making the bridge lean back against the wall, to remove the strain 

 from its chains or ropes, and to prevent it from falling, even should they 

 be broken. It may be, however, that into these grooves fitted some lever, 

 or other contrivance for working the bridge, for their surfaces are not worn, 

 as they must have been had the pivots rubbed along them ; and where they 

 occur, there are no lioles above for the passage of the drawbridge chains 

 into the portcullis chamber. 



The defences of the great postern are singular. The grooves, which in 

 the other cases mark the portcullis slides, here stop abruptly a little above 

 the arch. They are too deep for gates, and were probably filled by a de- 

 fence similar to a portcullis, but which was received into a cavity below. 

 Indeed, as there is only a lofty wall, and no chamber above the postern, the 

 regular plan was inadmissible. 



There is a contrivance for the further defence of a gate, consisting of 

 an oblique opening downwards from the sill of a window, a sort of sink, 

 employed in two places in this castle ; the one over the door of the eastern 

 inner gate-way, and the other over the door of the north-west principal 

 bastion towers y in both cases evidently with a view to the holding out the 

 towers, when the enemy had gained the inner court. 



The battlements and parapets throughout the castle are of a very plain 

 description. They are massy and flat-topped, the coping being a rough 

 slab of sandstone. Their height and thickness, together with that of the 

 rere-wall and the width of the rampart walk, may be always deduced from 

 a careful inspection of the walls or towers against which they terminate. 

 The parapet and rere-wall are usually of the same height, and nearly as 

 high as the top of the doors leading to them. 



