From the western door there is a clear passage through the centre of the nave, called the aisle, signifying the straight and narrow way from the seat of darkness to immortal life. On each side of this aisle are seats for the laity, with room for standing and kneeling. The nave was usually divided from the chancel by an open screen of wood or stone, signifying that although the Christian might have some insight into the mysteries of the priest's office, at the same time these were to be partly concealed from his view. The rood screen was so called from the fact that the great Rood, or Crucifix, stood above it, not always on the screen itself, but on a separate beam, to which was often attached a rood loft or chamber. In early days, the lessons were read from the top of the rood screen, and in many of our churches the stairways leading thither have been retained. [Illustration: Examples of Gothic Windows. Early English. Decorated. Perpendicular. See also page 59.] In churches where the screen has vanished, the division of the nave from the rest of the church is plainly marked by the chancel arch. The chancel is emblematic of the Christian perfection, of the Church triumphant in heaven. In an old church, a piscina is nearly always found in the chancel, and here, too, were the sedilia or seats for the officiating clergy, the prior, sub-prior, and the deacon, the last-named occupying the lowest seat. Founders' tombs also nearly always occupy positions in the chancel, and these tombs differ from all others in that they form an integral part of the structure, and could not have been added after the church was completed. Another thing sometimes to be seen is the ambery, or aumbry, a small cupboard let into the chancel wall, in which were kept the communion vessels, the chalice, paten, etc. The great object of interest, however, in the chancel, is the altar, which Archbishop Laud directed should be enclosed by rails, so that although the people may draw near, they cannot touch the holy table, but must accept from the hands of the priest those gifts of which he is the minister from God. Altars are fully described in a following chapter, but we may here note that the reredos, so universally found in our cathedrals, abbeys, and in many of our churches, forms no part of the altar, and the Court of Arches has decided that there are no altars in the Church of England, but only communion tables.