Elements of a Cathedral

"Canon law does not specify the form and dimensions of the cathedral; nevertheless, it supposes the edifice sufficiently spacious to accommodate a large assemblage of the faithful on the occasion of elaborate pontifical ceremonies. If possible, the choir, sanctuary, and nave should be of suitable proportions, and besides the altar and general equipment necessary in other churches, the cathedral should have a permanent episcopal seat. The word cathedra, so expressive in the language of antiquity, has gradually been replaced in liturgical usage, by throne (thronus) or seat (sedes). According to the "Caeremoniale Episcoporum" (I, c. xiii) the throne should be a fixture and placed either at the extreme end of the apse-- when, as in the ancient basilicas, the altar is in the middle of the church and the celebrant faces the people--or else to the front of the altar on the Gospel side, when the altar is placed, as is usual, against the rear wall and the celebrant turns his back to the people. In either case the throne should have an approach of three steps and be surmounted by a canopy as a sign of honor. When the bishop pontificates, the steps of the throne should be carpeted and both the throne proper and the canopy be decorated with costly materials. The thronos of the Greek bishop is the same, except that its very high back is surmounted by an icon, or sacred image. The cathedral should also have its baptismal fonts. Finally, not only should it have an ample supply of the sacerdotal vestments and sacred vessels required in all churches, but also of the vestments and pontifical insignia used by the bishop in solemn ceremonies."

(The Catholic Encyclopedia, Volume III. Published 1908. New York: Robert Appleton Company. Nihil Obstat, November 1, 1908. Remy Lafort, S.T.D., Censor. Imprimatur. +John Cardinal Farley, Archbishop of New York)