Caerphilly Castle, Glamorgan. 331 seems always to have been long enough, when up, to cover the gateway. The method of hanging the bridge also varied. On the sides of some of the portals a stone has been inserted, into which the hori- zontal pivots of the bridge (of iron, from the small size of the pintle or hole) fitted ; but, connected with the place for the gudgeon or pivot is another groove, which passes up at an angle of forty-five degrees 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 effectually to shield the upper part of the door, to pre- sent 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 con- trivance for working the bridge ; where they occur, there are no holes above for the passage of the drawbridge chains into the port- cullis chamber. Similar grooves are seen in the upper gatehouse at Chepstow. The defences of the great, or water, postern are singular. The grooves, which in other cases form the portcullis slides, here stop abruptly a little above the arch. They are too deep for the hinges of gates, and were probably filled by a defence similar to a port- cullis, 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 further contrivance for the defence of a gate, con- sisting of a sort of shoot, opening obliquely downwards from the sill of a window, employed in two places in this castle ; one over the door of the eastern inner gateway, and the other over the door of the north-west principal bastion tower ; in both cases evidently with a view to the defence of the towers when the enemy had gained the inner court. The battlements and parapets throughout the castle are of a v^ery plain description. They are massy and flat topped, the coping being a rough slab of sandstone. The height and thickness, together with that of the rerewall 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 rerewall are usually of the same height, and nearly as high as the top of the doors leading to them. The embrasures are contained within parallel sides, and bear a small proportion to the merlons, which latter are each perforated by a loop. These details may be seen upon the summit of the leaning tower, or, more conveniently, upon the northern curtain, toward the north-west bastion tower. It is evident, from the un- finished character of the battlements, and the flat undressed coping, that they were intended to be masked by an exterior gallery, or brattice of wood, resting on the stone corbels which still remain.
