are used as confessionals. At the east end of the nave is the organ gallery, accessed via a staircase in the northeast corner. In the corresponding south-eastern corner is the original baptistery, now used as a Chapel of Saint Josemaría. The main portion of the church is divided into five bays, with arcades separating the nave and the flanking aisles. Each arcade is supported on six Jork Swedish red granite columns, worked and polished in Scotland. These columns are arranged so as not to intercept the view of the high altar from the aisles. The columns have capitals of foliated form artistically treated so as to appear alike, but the detail of each differs materially. The columns have marble bases, which, in turn, are supported on smoothly rutted Malmsbury bluestone plinths. The columns each bear a polished brass plate at the base of the shaft, inscribed with the name of the parishioner or the parish organization who funded the cost of that column. Sanctuary and chapels St Mary's contains four side chapels in addition to the main altar. The sanctuary is flanked by a pair of chapels, dedicated to the Sacred Heart (south) and the Blessed Virgin Mary (north). Flanking these large chapels are two smaller chapels, which front the transepts, dedicated to Saints of Ireland (south) and Saint Joseph (north). All four chapels and the sanctuary, terminate in semi-octagonal forms. The sanctuary and chapels are separated from the nave and transept by a white marble altar rail, installed in 1927, which is pierced by repetitive quatrefoils. The sanctuary and each of the chapels are accessed via separate openings with ornate brass gates. The canted walls of the sanctuary and chapels have clusters of columns and half columns at their intersections. Some marble inlay is of Pyrenian (Spanish) rose marble; other columns are scagliola. Scagliola, which dates back to the 17th century or earlier, is a form of plastering which imitates marble, or other fine stone. Scagliola columns are traditionally made by forming a substrate of thin strips of metal or wood which are lathed and covered with a coating of lime and hair. The columns are then coated with a mix of gypsum plaster and glue, tinted accordingly. The dense and highly polished finish is achieved by rubbing with pumice, charcoal, linen cloth and, finally, felt impregnated with oil. The floor of the sanctuary and side chapels is covered