In the south alley was the refectory and the monks' common dining-hall. The original building is now entirely altered, though there remains beneath it a very early crypt, with plain, short square piers, and a simple quadripartite vault without ribs. Another portion is covered by a wagon-head vault. Whether the original refectory was of similar architectural character it is now impossible to say, as, whatever it may have been, it was removed early in the sixteenth century and rebuilt, and after the dissolution of the monastery was used by the Minor Canons of the church as a common hall. It seems to have fallen into a bad state of repair, and was again entirely reconstructed by Dean Sudbury (1661-1684), who was elected to that office immediately after the Restoration. He converted it into a library, to which use it is still put. The account of this building, given in the "Antiquities of Durham," is of sufficient interest to bear quotation. "In the _South_ Alley of the Cloysters," says our authority, "is a large Hall, called the Frater-house, finely wainscotted on the _North_ and _South_ sides; and in the _West_ and nether Part thereof, is a long Bench of Stone in Mason-work, from the Cellar Door to the Pantry or Cove Door: Above the Bench is Wainscot Work two Yards and a Half high, finely carved, and set with imboss'd Work in Wainscot, and gilded under the carved Work. Above the Wainscot was a large Picture of our Saviour Christ, the blessed Virgin _Mary_, and _S. John_, in fine gilt Work, and most excellent Colours; which Pictures having been washed over with Lime did long appear through it. This Wainscot had engraven on the Top of it, _Thomas Castell_, Prior, Anno Domini, 1518 Mensis Julij. Whence it is manifest that Prior _Castell_ wainscotted the Frater-house round about. "Within the Frater-house Door, on the Left Hand at entering, is a strong Almery in the Wall, wherein a great Mazer, called the Grace Cup, stood, which every day served the Monks after Grace, to drink out of round the Table; which cup was finely edged about with Silver, and double Gilt. In the same place were kept many large and great Mazers of the same sort.... Every Monk had his Mazer severally by himself to drink in, and had all other Things that served the whole Convent, and the Frater-house in their daily Service, at their Diet, and at their Table.... At these Times (at meals) the Master observed these wholesom and godly Orders, for the continual instruction of their Youth in Virtue and Learning; that is, one of the Novices appointed by the Master, read some Part of the Old and New Testament in Latin, during Dinner, having a convenient place at the _South_ End of the High Table, within a beautiful Glass Window, encompass'd with Iron, and certain Stone Steps, with Iron Rails to go up to an Iron Desk, whereon lay the Holy Bible....