of the nave and choir nearest the transept, while the pointed work is specially noticeable in the eastern half of the choir.[210] The first parts of the cathedral built were the three westmost or Norman bays of the choir, with their aisles, both the transepts, the crossing (afterwards altered) intended to receive a tower over it, and two bays of the nave, which served to form an abutment for the crossing. These portions, where unaltered, are said to be in the earliest style of Norman work in the edifice. The round piers and responds of the choir, the two south piers and one north pier of the nave (with their cushion caps), the main arches (with their label mouldings in the choir and transept), the round arched and labelled windows in choir, transept, and nave, and the interlaced arcades in the nave, all point to a somewhat advanced period of Norman work. The choir originally terminated with a central apse beyond the third pier. The Norman windows of the choir aisle have three external orders, with a label ornament in the outer order; the single shafts have cushion caps; the windows are largely splayed internally.[211] An interlacing arcade of round arches, with single shafts and cushion caps (some with volutes) runs round the north, south, and west sides of the transept. The large arches leading into the east chapels are part of the original structure, but the chapels were built later. The lower string-course of the transept is enriched with a four-leaved flower.[212] After the completion of these portions, attention was given to the continuation of the nave westwards for several bays. The north aisle wall opposite the three bays, west from the crossing, would appear to have been built early.[213] The buttresses are of flat Norman form. The north aisle doorway is pronounced to be Norman in detail, but has been restored at a later date; the south aisle doorway retains its old Norman arch and shafts in the interior, but has been altered externally. The nave piers were probably continued as far as the above doors about this time, with the triforium, but the upper part of the nave walls and the vaulting are later.[214] The transition style is prominently seen in the piers and arches of the crossing, and the windows in the choir nearest the main arches of the crossing, and the triforium openings into the transept, appear to have been altered and rebuilt at the time of this operation. The upper part of the north transept was probably raised and its windows inserted at this time; the raising of the south transept and the introduction of the rose windows is of somewhat later date.[215] This circular window is very similar to that in the east window of the choir. The chapels on the east side of the transept are of the advanced transition period, which, in Orkney, was probably the middle of the thirteenth century.[216] The completion of the nave would be next undertaken.[217] The apse was taken down, and the choir, with its