YESTER CASTLE 121 FIRST PERIOD rock, starting at the same point as the above passage. This staircase descends 44 feet, measuring on the slope of the stair, when it reaches a well sunk in the rock, which formerly contained water, although now filled up with stones. It seems to have been intended to cut the passage or staircase further, as it is left unfinished, with a face of rock at the end. Probably it has been meant to continue these unfinished passages as mines round the building, with a view to act as countermines wherever found necessary to resist the sapping operations of besiegers. In the north wall of the subterranean chamber there is a remark- able aperture with a flue or tunnel leading upwards, the purpose of which is at first sight matter of doubt and conjecture (sections, Fig. 93, and view, Fig. 95). There are deep slots in the wall as if for sliding beams to carry a platform, placed at a level about half-way between the two floors, and the corbels which supported these beams still remain. The position of these corbels and beam-holes, and the slope of the back of the aperture are peculiar, but the simplest mode of explaining them is to suppose that they formed part of a fireplace. The sloping back of the chimney is not unusual, especially when the hearth was covered with a hood. Hoods, being often of wood or plaster, have generally disappeared. In this case the hood would be constructed of wood, the beams carrying it being inserted in the wall holes and supported by the corbels beneath. The hood would be finished with plaster and sloped back to the wall towards the top of the chamber. The sloping back of the flue in the wall would thus correspond with the slope of the hood. The hearth would be on the level of the floor and the smoke would rise perpendicularly along the straight part of the wall till it reached the hood. The use of the side corbels, which is at first unintelligible, is thus explained. They are the brackets frequently introduced at the sides of fireplac.es to carry lamps, of which a fine example occurs at Tullyallan. A fireplace of almost identical construction with the one at Hailes occurs at the castle ot Villeneuve-les-Avigiion, already referred to. The chimney of Dirleton Tower (Fig. 91) is covered with a stone hood, and the back of the fire- place begins to slope at the hearth, but in other instances, as at Dun- donald Castle, the slope begins at some distance above the floor, as it does here. Possibly this chamber served several purposes. It has clearly been intended for a military post, where soldiers might assemble, and from which they might sally out by the secret door above described. It might also be used for secretly introducing reinforcements and provisions. This chamber, with its secret rock-cut passages and stairs, strongly recalls similar constructions in early French castles, such as Arques and Roche Guyon. Underground passages were also not uncommon in the early English castles, as at Windsor, where a passage was tunnelled from the castle down to the edge of the river. At Dover, also, numerous similar passages are cut in the chalk rock round the castle.
