The rood screen behind the altar, which is sometimes erroneously called St. Cuthbert's screen, is of fourteenth-century work, but much restored, and is pierced by two[6] doorways, which were used when processions passed from the nave into the choir. The doors themselves are fourteenth-century work. Against this screen once stood three altars. The northern one was dedicated to St. Thomas of Canterbury and St. Oswyn, King of Northumbria; the central one to the Holy Apostles, the confessors, and St. Benedict; and that on the south to St. Mary. These once stood against the western faces of the Norman piers of the south arcade of the nave, which fell in the fourteenth century. These piers doubtless corresponded with those we still see on the north side, and were probably similarly decorated with frescoes. The south arcade at its eastern end differs entirely from that on the north. This part of the church was rebuilt after the fall of part of the Norman arcade. The five Early English bays to the west are divided from the Decorated ones to the east by a massive pier, generally supposed to be Norman, but probably rebuilt. The northern face of this runs up as a pilaster buttress to the roof; the string round it in continuation of that below the triforium is carved with tooth ornament. West of this we have tooth ornament, to the east the characteristic ball flower. The junction of the two styles is shown in the illustration below, from which it will be noticed that, though there is a general resemblance in the bays on either side of the dividing pilaster, yet the details are different. To the east we see shields below the triforium string, and heads at the termination of the hood moulding. The head shown in this photograph is possibly that of Master Geoffrey, master mason to Abbot Hugh of Eversden; the others passing on to the east are probably those of Edward II., Queen Isabella, and Abbot Hugh. The shields, also counting from the west, are those of England, France, Mercia, England, Edward the Confessor, and England. The hood mouldings of the triforium and clerestory also terminate in heads, some of them grotesque. The Decorated piers were found by Lord Grimthorpe in a very unsound condition, not on account of any defect in the foundation, but on account of the bad mortar in which their rubble cores had been set. This had become dust, and tended to burst out the ashlar casing: this shell was indeed doing all the work of supporting the weight resting on the piers. Lord Grimthorpe shored up the arches, and in large measure rebuilt the piers of larger stones. He says: "It took no small trouble and scolding to get these worked as roughly as the old ones, so as to make the work homogeneous and bewilder antiquaries." This sentence shows the false principles on which Lord Grimthorpe sometimes worked; necessary repairs should never be executed with a view to make the work appear as old as that the place of which it takes.