VAULT (OF. volts, route, rout le, Fr. mate, vault, from Lat. ro/atus, p.p. of volrere, to roll; with (loth. wahrjan, AS. wcahrian, Fog. wallow). A term used to designate the cov ering of a building constructed of masonry or in imitation of masonry in curved surfaces, as dis tinguished from ceiling or roof. The principal classes of vaults are: the dome. the barrel vault, the groin vault, and the rib (or Gothic) vault. Each of these classes has many sub-varieties. (For the different forms of the dome, such as the Pelasgic, Assyrian, Roman, Byzantine, Moham medan, Gothic, Renaissance, Russian, the false dome, the low dome, the high dome on a drum, the bulbous dome, the ribbed dome, the dome on pendentives, see the article on Doran].) It was a form of vault that flourished mainly in the Orient, being only slightly used in Western Eu rope until the late Middle Ages and in Hellenic lands only by the Byzantine school.
The earliest form appears to have been the barrel or tunnel Vault, a continuous vault usual ly of either semicircular or pointed cross-section. This vault was used by the Babylonians and Assyrians in both these forms, not only in sub terranean passages, as at Nippur and Nintrud, but in the large palace halls, as at Ichorsabad. The Egyptians, on the contrary, seldom used it where it would show. It was known, although used only in this inconspicuous fashion, to all the Mediterranean peoples—the Hittites, Pelasgians, early Italian races, and Etruscans—competing with the dome in their subterranean construc tions such as tombs, treasure-houses, drains, etc. The Cloaea Maxima shows how the early Ro mans adopted it, and finally developed it as one of their favorite ways of covering large interiors above ground by the sided dome and groin vault. Used inconspicuously by Byzantine and hardly at all by early Christian art, it was adopted by certain schools of Romanesque architecture, es pecially in France, as in Provence and Burgundy. Gothic art discarded it, but the Renaissance re vived it, as it did so many Roman forms.
The groin vault was formed by the intersection of two barrel vaults and appears to have been first used to any extent by the Romans of the late Republican and Imperial periods and by them transmitted to later schools. It could be used only in a square vaulting compartment and had no elasticity of shape. In early mediawal schools it was even more generally used than the barrel vault, especially over the side-aisles of churches and other narrow spaces. When strengthened by ribs at the groins it developed into the Ro manesque vaulting of the Lombard, Rhenish, and Norman schools, winch was superseded by the Gothic form of ribbed vault.
While the quadripartite ribbed vault might he superficially taken to be a groined vault with the addition of surface ribs along the diagonal in tersecting edges, the wall line, and the line of aivision between the neighboring vault, this would be a fundamental error, because in the ribbed vault each compartment between ribs is an independent structure transmitting thrust to the ribs, and the ribs themselves form an inde pendent framework. There are quadripartite, sexpartite, and other forms, according to the number of such compartments; domical ribbed vaults have inure; the curved lines of Gothic choir-aisles and chapels led to other intricate and irregular combinations, so that there is :in almost infinite variety in ribbed vaulting. The history of its origin and its importance as the basal unit in Gothic architecture is explained under GOTII IC Alien ITECTI E. ( For fancy ribbed vault, see Rut.) For various unusual forms, such as cloistered vault. wagon vault, the various forms of conical vaults, as well as for a technical study, consult "Vault," in Sturgis, Dictionary of ilrehiteeture (New York, 1902). See also "Con struction" and "Vonte," in Viollet-le-Duc, Dic tionnuire misonnte dr Parch it rehire (Paris, 1854 6`O ; Ilaase, her Grwolbebau (Halle, 1900).