"This pier and the south aisle of the choir beside it appear to have been restored by Abbot John Hall (appointed 1478), whose name occurs on the pier and on one of the bosses. The south-west pier of the crossing has also been rebuilt. This work was carried out by Abbot Thomas Cranston (appointed 1482). On a shield on this pier are carved the arms and initials of Abbot Cranston--three cranes and two pastoral staves--saltierwise. The same abbot's initials are placed on the north side of the west arch of the crossing, where the chamfer begins, and on the lower part of the north-west pier. The south-west pier, the north-west pier, and the arch between them would thus appear to have been rebuilt by Abbot Cranston. The base inserted by him is different from the old Norman base. "About half-way up the south-east pier, rebuilt by Abbot Hall, the springer of an arch may be seen projecting to the west. Abbot Hall had evidently intended to throw an arch across the transept at this point, but Abbot Cranston changed his plan and the arch was not carried out. The mouldings of the portions executed by the two abbots differ in their respective parts of the structure. "To the north of the original Norman north transept an addition to the transept has been erected. It is cut off from the old transept by a wall, and thus forms a separate chapel, measuring 27 feet in length by 22 feet in width internally. This chapel is vaulted with the pointed barrel vault usual in Scotland in the fifteenth century, and, consequently, the side windows are low, their pointed arch being kept below the springing of the vault. The window in the north end wall, however, is of large dimensions. The windows are all filled with good fifteenth century tracery, similar to that in the restored south aisle of the choir. This part of the edifice is now used as a mortuary chapel for the family of the Marquess of Lothian. The tower over the crossing is 33 feet square and 86 feet in height. It contains three pointed and cusped lancets on each side, and is without buttresses. It appears to have been erected about 1500. At the top, near the north-west corner, are engraved the arms and initials of Abbot Robert Blackadder, who was afterwards promoted to the offices of Bishop and Archbishop of Glasgow. He was appointed to that see in 1484, and died 1508. His arms are a chevron between three roses."