Except for the number of buildings composing it, the palace had little to distinguish it from a nobleman's mansion. The latter consisted of a principal hall, where the master of the house lived, ate and slept, and of three suites of chambers, disposed on the north, the east and the west of the principal hall. In the northern suite the lady of the house dwelt, the eastern and western suites being allotted to other members of the family. Corridors joined the principal hall to the subordinate edifices, for as yet the idea had not been conceived of having more than one chamber under the same roof. The principal hall was usually 42 ft. square. Its centre was occupied by a "parent chamber," 30 ft. square, around which ran an ambulatory and a veranda, each 6 ft. wide. The parent chamber and the ambulatory were ceiled, sometimes with interlacing strips of bark or broad laths, so as to produce a plaited effect; sometimes with plain boards. The veranda had no ceiling. Sliding doors, a characteristic feature of modern Japanese houses, had not yet come into use, and no means were provided for closing the veranda, but the ambulatory was surrounded by a wall of latticed timber or plain boards, the lower half of which could be removed altogether, whereas the upper half, suspended from hooks, could be swung upward and outward. Privacy was obtained by blinds of split bamboo, and the parent chamber was separated from the ambulatory by similar bamboo blinds with silk cords for raising or lowering them, or by curtains. The thick rectangular mats of uniform size which, fitting together so as to present a level unbroken surface, cover the floor of all modern Japanese houses, were not yet in use: floors were boarded, having only a limited space matted. This form of mansion underwent little modification until the 12th century, when the introduction of the Zen sect of Buddhism with its contemplative practice called for greater privacy. Interiors were then divided into smaller rooms by means of sliding doors covered with thin rice-paper, which permitted the passage of light while obstructing vision; the hanging lattices were replaced by wooden doors which could be slid along a groove so as to be removable in the daytime, and an alcove was added in the principal chamber for a sacred picture or Buddhist image to serve as an object of contemplation for a devotee while practising the rite of abstraction. Thus the main features of the Japanese dwelling-house were evolved, and little change took place subsequently, except that the brush of the painter was freely used for decorating partitions, and in aristocratic mansions unlimited care was exercised in the choice of rare woods. Buddhist Temple Architecture.