The sailing properties of the _balza_, or any other similar raft, must have been greatly impeded by the resistance offered to the water by the ends of its numerous beams. In order to diminish the resistance, the obvious remedy was to use only two beams, placed parallel to each other at a distance apart, with a platform laid on cross-poles between them.
Of this kind we find a vessel used by the Tasmanians, and described by Mr. Bonwick, on the authority of Lieut. Jeffreys. The natives, he says, would select two good stems of trees and place them parallel to each other, but a couple of yards apart; cross-pieces of small size were laid on these, and secured to the trees by scraps of tough bark. A stronger cross-timber, of greater thickness, was laid across the centre, and the whole was then covered by wicker-work. Such a float would be thirty feet long, and would hold from six to ten persons (Herbert Spencer, _Descriptive Sociology_ (London, 1874), No. 3, Table V).
In Fiji, Williams describes a kind of vessel called _ulatoka_, a raised platform, floating on two logs, which must evidently be a vessel of the same description as that used in Tasmania.
From these two logs were derived the double canoe on the one hand, and the canoe with the outrigger on the other.
A link between the catamaran and the outrigger canoe is seen in a model in the India Museum, from Madras. It consists of the usual catamaran, already described, of three beams lashed together, the longest being in the centre, across which are attached, their ends extending on one side, long outrigger poles, to the extremities of which, parallel, and at some distance from the catamaran, is fastened an outrigger log, of smaller size and length, pointed at both ends, and boat-shaped, exactly like those used with the outrigger canoes to be hereafter described. When the art of hollowing out canoes was introduced, then one canoe and one log, or two canoes, were employed, as the case might be. This I consider to be a more natural sequence than to suppose the outrigger invented as a means of steadying the dug-out canoe.
The outrigger canoe, and its accompanying double canoe, is used over the whole of the Polynesian and Asiatic islands--from Easter Island on the east, to Ceylon and the Andamans on the west. Their varieties are also, in some cases, continuous; and I will endeavour to trace the distribution of each, commencing with the canoe with the single outrigger.