That these four towers have been mined and blown up with gunpowder, at some period when the effects of that agent were well understood, is evident on inspection. The mine has been sprung near the centre of each tower, and has produced effects, differing in degree only, upon each. That on the north-east is altogether levelled, on the outside, entirely to the ground, crushing in its descent the very bastion on which its foundation rested—on the inside, the door and a portion of wall, as high as the curtain, only remain. The destruction of the north-western tower has not been by any means so complete. Only a third of its outer circumference has fallen, and the rest, deprived indeed of its floors, remains as firm as ever. The portion which has fallen lies in fragments upon the neighbouring bastion.
At the south-western tower the mine has operated outwards; the whole of the outer portion has fallen upon the bastion and into the ditch, but the inner strip connecting it with the rest of the building, and containing the entrances to the several stories, has been protected by the outbuildings on its southern side, and is unshaken.
The last, or south-eastern, is the celebrated leaning tower, the obliquity of which has been much exaggerated, and absurdly accounted for. In the case of this tower the mine has exploded in a contrary direction from the rest, and the inner portion, with the adjoining curtain, has been thrown into the court, while the outer portion remains standing, although the force of the explosion has thrown the mass out of the perpendicular, so that it overhangs its base, towards the south-west, nine feet. The parapet at its summit remains quite perfect, and is the only one in the castle that is so.
The neighbourhood of these four towers, and the intervening gatehouses, upon which the force of the gunpowder has been chiefly employed, is a chaos of ruins; subverted masses of the gallery, staircases, the vaulting of large portions of the chambers themselves, lie in confusion upon the ground; and the thin mantle of vegetation which has enveloped them, although it adds much to their picturesque beauty, increases in no slight degree the difficulty of accurately comprehending their original disposition.
Throughout this immense building the iron work, even to the staples of the doorways, has been removed; nor is there any lead to be found in the sockets of the window-bars.
The hewn stone forming the door-frames, window-cases, newels of the well-staircases, and in some instances the stairs themselves, have been rudely wrenched away, with damage to the walls, for the purpose, probably, of converting them into lime.
Portcullises, stockades, doors, with the roof of the hall, and every particle of timber in the place, have long been removed. Every staircase, gallery, and chamber is pervious to the rain, and exposed to the pernicious force of the frost, yet such and so durable are the materials, and so firm the mortar with which the whole is cemented, that time and weather alone have produced but trifling injuries upon the pile, compared with the wilful destruction of the hand of man.
Before arriving at any general conclusion respecting the age of Caerphilly, it will be proper to make a few remarks upon certain details, on which those conclusions in some measure rest.
And first of the doorways. With certain exceptions shortly to be enumerated, the doorways throughout the building are of the same general character. The arches are “drop,” that is to say, they are obtusely pointed arches, whose centres lie below their spring. This is obviously the best form of the pointed arch for the portals of a castle, and it is that usually employed in the military structures of the Edwardian period. With the same exceptions, the arch-mouldings are composed of a five-sided rib, upon the front and widest face of which a smaller rib, of the same figure, is placed. This pattern of rib-moulding is also very commonly employed in castles.
The principal portals, together with the doors leading from the first story of the towers upon the ramparts, are defended by portcullises, working in a D-shaped groove. This groove passes up as a chase or slot into the chamber above; but there is no evidence of the sort of contrivance employed in raising the portcullis. The portcullis, however, might have been raised by mere manual exertion, and a bar thrust across would be sufficient to retain it securely when raised. The sills are destroyed, so that it does not appear whether the points of the portcullis were received into, or had worn, small holes in them. Besides the portcullis, the larger portals are provided with a chase, but without side grooves, intended, as is presumed, to allow of the use of a sort of wooden frame. Also, in the main portals are four or five square holes or meurtrières in the arch, through which beams to form a stockade might be dropped. It may be observed further that although some of the portal passages are of considerable length, yet the ribs of their vaults are all transverse, never passing diagonally from an angle towards the centre, in the manner employed at Caldecot and elsewhere, to vault a compartment of such passages.