Within the castle all was bustle and business. Harness was mended and bullets were moulded, bows restrung and arrows feathered, axes and swords whirred on the grindstone, huge cauldrons were prepared wherein to heat water to pour upon besiegers' heads; and even the countess and her ladies helped to carry stones with their own fair hands, and pile them ready for the use of the slingers. Meanwhile the swallows wheeled and twittered overhead as they wheel and twitter now; and down in the woods the merles and mavises sang on undisturbed by the tumult, while swans were marshalling green-grey cygnets across the pools in the marshes of the Cowholme. CHAPTER XXII. A SUBTERRANEAN CONFLICT. The besiegers on their part had not been idle. They had established quite a _menagery_ of mechanical contrivances, rejoicing in the zoological names of tortoises, sows, and cats, to protect their approaches to the white walls of Blauncheflour, and under cover of these they had cut a channel to the castle ditch and drained the water from it, so that it was as dry as at present, though, instead of growing fair greenery of bushes and flowers, it showed a bottom of parched, foetid mud under the hot summer sun. They had thrown up large mounds of earth at intervals around the ballium, and upon these had built up towers of wood overtopping the walls. These were furnished with drawbridges which could be let down at pleasure upon the merlons of the battlements, so to give ingress to their men-at-arms; their upper storeys serving to shelter archers and slingers, while from the lower, battering-rams were sturdily plied, and the warrewolves flung their stones and balls of lead. These towers had cost them many good lives, for not one had been established without a fierce struggle. Sally after sally had been made from the castle, but, in the end, numbers prevailed, and at last their impertinent wooden crests were reared above the Caen stone of Blauncheflour. Those within were, however, more troubled by the mines which their assailants had run from the bottom of the moat beneath the foundations of the castle; for although these had been met by countermines, and many a furious combat had taken place in these uncanny lists, each mine meant a point to be guarded with jealous care, and was a source of weakness and anxiety; demanding exhausting sentry duty from the already over-burdened garrison.