Attention has been drawn to the various changes in technique which developed locally. The common walled houses built of poles were based on the memory of central Polynesian construction with wall plates and purlins lashed to the rafters but the thatch rafters changed to thatch page 134purlins to suit the local thatch material. The sunken floor was introduced to meet the winter cold. The sunken floor with the reduced external height of the side walls led to the door being placed at one end and the open porch was an easy addition. The close thatching of the walls led to the introduction of a window for ventilation.
The use of dressed timber for the superior houses was facilitated by the abundance of large trees and the consequent development of skilled craftsmen with an inexhaustable supply of good timber. The development of the carved meeting houses was stimulated by the social ambition of chiefly families and their tribes. The use of the tenon and mortice join between rafter and wall post did away with the wall plate as a support for the lower ends of the rafters. A form of join between rafter and wall post, however, occurs in Hawaii with the positions reversed, for an upright
Fig. 16. Rafter decoration. a, b, Polynesian lashing; c, Maori painting.
tenon was made on top of the wall posts and the lower ends of the rafters were forked to rest against the wall post tenon. The long wall plate, however, was retained to maintain the upper spacing of the wall posts. In Maori construction, the wall plate was dismembered and represented in sections by the kaho paetara
. The most extraordinary change was the abandonment of lashing the purlins to the rafters and substituting the method of slinging them with the tataki
rope or using the subsidiary back rafter (heke tuara
) described by Ngata. Such a drastic change must have been due to some definite reason. It may be that the narrower purlins and the wide rafters did not tie well together, but it seems more feasible that in the great development of interior decoration which took place the craftsmen did away with the lashings in order to provide a clear field on the rafters for decoration by painting and thus keep up with the advances that had been made in carving and decorative reed work. The latter possibility is contradicted by the use of the same technique with the plain rafters of the whare punt
, but this may be an instance in page 135
which a technique established in a superior building may have been copied in an inferior structure. The difference in the decoration of the Polynesian rafters by lashing and the Maori rafters by painting is shown in Figure 16.
The use of the ribbed flange on the back of barge-boards, amo supports, and the wall boards of some raised storehouses is worthy of note. The posterior flange provided a means of fastening boards at the back without the lashings interrupting the carving on the front surface of the boards. The elaborate carving of the pataka storehouses was also stimulated by the social ambition of chiefs to add to their prestige. Food was all important and the carved storehouse directed attention to the wealth of supplies supposed to be contained within.