Part II.—History of Construction.

Two leading forms, viz.: The circle and the rectangle.—The circular-domed hut the original type of domestic habitation throughout Western Europe.—Models of the early house used as cinerary urns of a very early date in Italy and Germany.—Connection of Germanic races with the early dwellers in Troy.—Survival of the domed form in the snow huts of the Esquimaux.—Domed tombs of the early Greeks.—The "sepulchral couch" of Danaë at Mycenæ.—The modern Turkish hut a typical example of rectangular construction.—Flat timber roofs of Persia and Assyria.—Flat stone roofs of Egyptian temples and of cities in the Lejah.—Lycian tombs simply marble copies of rectangular wooden framing.—Domed roofs of Grecian tombs built in horizontal courses; same system employed in Etruscan tombs and in the vaulted roofs of Central America.—Façades of stone in imitation of upright posts and trellis-work.—Type of early Central American hut, with sloping roof.—Flat roof of Circe's palace mentioned by Homer.—Rectangular types of building in the cliff fortresses of Arizona.—Terraced roofs of the towns of the Pueblo Indians.—Plans of ancient Peruvian cities built under Inca rule.—Marble plan of Rome in the time of Nero.—Arched corridors at Nakhon Wat, in Cambolia, built in horizontal courses.—Indian domes built in horizontal, not radiating, courses.—The true arch brought into general use as a constructive feature by the Romans.—Substitution of the arch for the architrave.—The abandonment of the lintel as a constructive feature, the key to the origin of the arched styles respectively known as Gothic, Lombardic, Moorish, and Saracenic.—Tunnel vaulting.—Intersection of cross vaults.—Twisted groins.—Methods of striking an ellipse not known to the Romans.—Ribbed vaulting: its principles.—Introduction of the equilateral triangle as a canon of proportion.—Scientific construction, as distinguished from mere building, first introduced by the Romans.—Collapse of the constructive art in Britain on the departure of the Romans.—Revival of art in England about the tenth century.—Development of Gothic architecture in the fourteenth and fifteenth centuries.—Collapse of Gothic art with the Reformation.—Revival of classical forms in later times, the architrave again taking the place of the arch as a constructive feature.