The north-west tower has entirely disappeared, but its position has been ascertained to have corresponded with that of the south tower. Above the existing arch from the tower into the south aisle, and on the east side of it, a small portion of an arch of the triforium may still be observed (Fig. 503). A small shaft with cap and a portion of the arch yet remain. In Grose’s view some fragments of the clerestory are also shown, but they no longer exist. To the north of the south tower pier a strong wall, 6 feet in thickness, has been erected across what was originally part of the nave. This, Mr. Galloway thinks, was probably built as a reparation of the fourteenth century, the structure having probably suffered injury during the wars of independence. Whether the wall was erected at that time or not, there can be little doubt that it was constructed after the demolition of the original west front and tower, as a substitute for the former. The wall is built across the church between the east faces of the two towers, thus leaving the high arches of the towers, if they then existed, outside the edifice. It seems probable, however, that the south tower had by that time been partially demolished, and its ruins have remained ever afterwards exposed to the weather. Hence the extremely weather worn appearance the stones now present. The north tower, we know, remained complete till this century. It is shown by Grose, and an account exists of its being struck by lightning in 1805, and of its fall five years thereafter. A new tower has, in recent times, been erected on the site of the old north tower. This renewed west wall has a plain pointed doorway and a lofty double window (see Figs. 502 and 503), with a simple mullion and transome of rather indefinite design. The doorway is extremely plain and small, being only about 3 feet in width, and having a double splay on the jambs and arch.