[From Castle Rushen, Armitage Rigby, 1927]
EFORE leaving this side of the Castle we may notice that two towers of the curtain wall have both ground and first floor chambers opening on to the outer ward, beside the room above , opening on to the alure, or parapet walk. The ceiling of these chambers has often been pointed out as strewing that these towers are the most ancient part of the Castle. They are formed by incorbellation; that is, the projecting of each stone further into the room than the stone below it. Though this is a very early method of covering in buildings, it is a method which was also not uncommonly used for small and unimportant buildings up to a very late period, particularly where such excellent stone could be found for the purpose as was available in this case, and in these towers its use can be accounted for by the want of abutment for vaulting. There does not seem to be any reason for supposing them to be older than any other part of the curtain wall, which seems to be entirely of the 14th century.
Continuing round the outer ward we notice further foundations which are not suggestive of any particular use. In this connection a curious projection from the West Tower should be noticed, which looks like the springing of an arch, but remains at present somewhat of a mystery.
Opposite to this is a well in the curtain wall, which is here thickened out to accommodate it. It is shallower than the other wells, and there are steps leading down to the water. The spring was probably found during the building of the wall, and the wall then built round it forming a most useful and convenient water supply.
The following quotation from the " Acts of King Stephen" well illustrates the importance of a good water supply in case of siege. Referring to the siege of Exeter, the author says:-" The King had been detained before the Castle nearly three months, and had paid as much as 15.000 marks in various expenses. Then, however, the Almighty Disposer of events being willing to bring his labours to an end, dried up the springs which fed two wells within the Castle. . . . The wells being dry, they had recourse to wine to supply their necessities; and that too was speedily exhausted, as they were forced to use the wine in making bread and in cooking their food. They consumed it, also, in extinguishing the firebrands which the King's engineers threw into the castle to fire their warlike machines and; barracks; so that the wine thus failed as the water had done. Having now nothing to drink, their sufferings were extreme and they were reduced to a state of the utmost debility. For man's body can only be sustained in health and vigour by a sufficiency of nutriment, without which it becomes feeble and weak. Worn to extremity . . . the garrison held consultations as to surrendering the Castle on their lives being spared."
The last foundations we shall notice are those of a small building supposed to have been a chapel, of which the retaining wall of the causeway from the Gate House to the inner ward formed the East wall. The walls are now less than three feet high and are marked on old plans as " ruins of chapel." About 100 years ago the ruins were thrown down, and a house was built upon them for the Governor of the prison. This house was taken down as part of the restoration just completed, and the foundation walls of the chapel are once more exposed to view.
Among the debris were found some tiles of simple pattern, apparently of the 13th century and exactly similar to tiles found at Rushen Abbey; also some leaded glazing which was unfortunately so mangled that it is impossible to identify the pattern. Such pieces of glass as were found do not appear to have been stained in patterns, but they differ slightly in shades of bluey green, and it is difficult to say how much of this difference is due to art, and how much to their long rest underground in company with various materials. Clay, mortar, and soil containing decomposed matter would each probably have a different effect. Some of the pieces have beautiful irridescent shades) said to be due to the presence of ammonia in the soil.
Presumably this building is the chapel referred to by the author of " Brittannica Curiosa," and previously quoted as follows: " Here also is a fine chapel where divine service is celebrated morning and afternoon." The foundations cannot be said to suggest a fine chapel in point of size, the interior dimensions being 26 feet by 11 feet, but it may have contained features to compensate for this. It would seem to have consisted of two stories, of which the lower was probably used as a stable, judging from an arrangement of stones at the South end, suggestive of a trough or manger. The upper floor would be the chapel which was no doubt entered from the causeway, and would extend over the passage leading to the basement of the Gate House.
The chapel is evidently a later addition, and no part of the original scheme of the Castle. There are reasons for supposing that it was built about the same time as the Derby House (1644):-
1. The walling is of poor quality and jointed with clay instead of mortar, a common practice in the 17th and 18th centuries.
2. Mediaeval tiles, identical with those found at Rushen Abbey, were discovered among the debris. Rushen Abbey was dissolved by the Act of 1540, and the third Earl of Derby was appointed commissioner to carry out the dissolution and sale of effects. He is said to have bought all the effects himself, and this would account for his descendant having the tiles.
3. The building of the Derby House provided a reason for erecting a chapel in a castle already containing both a chapel and an oratory; for these are on the top floor of the inner ward which would then be used only for the retinue, and would be inconvenient of access from the new house.