AISLE, i1 (Fr. ails, wing, from Lat. alit, con tracted from oxi//o). An architectural term meaning the lateral section of the interior of any building which is divided by rows of piers or eolumns. In such interiors the higher and broader central section is called the nave; the narrower, lower sections are the aisles, divided from the nave or from each other by the lines of supports. There are a few cases of such an arrangement in (Ireek temples. The develop ment of interior-- of this type came with the rise of the Christian basilica or church in the fourth century, when the smaller churches had two :11111 t he larger ones four aisles on either side of the central nave. In contemporary cirenlar or polygonal building; — especially baptisteries, mausoleums, and chapels— the central dome was often encircled by taw or more concentric lines of arcades, forming aisles with lower ceiling or vault. When, in the Middle Ages, the upper parts of the church—transept and choir—were so much enlarged under monastic influence and the development of eathedral architecture, then the aisles were continued around the transept and the apse, thus adding great richness to the interiors. In a few eases there were as many as
three aisles on each side of the church. They varied very much in height., according to schools, periods, and methods of construction: and in some schools. (Lombard, Norman. Byzantine, Early Gothic, etc.), they were surmounted by open galleries, and scmetimes by closed galleries (south of France) ; while in other eases, espe cially in the early vaulted Romanesque, the vaults of the aisles reached almost as high as those of the nave.
There are several improper uses of the term: in the case of hall-chur•hes with two, three, or more naves of equal height. these divisions are sometimes incorrectly called aisles. Also, in modern usage it is wrongly applied to the pas sageway between two rows of seats in a build ing. See Cit•ncit.