Ribs
About fifty in number ([Figs. 91], [92]) are split with the grain (F, [Fig. 92]), so that the heart side of the wood will be on the inner side when the rib is bent. The wood bends better this way. They must be perfectly straight-grained and free from knots. Ribs for the middle are four inches wide, ribs for the ends about three inches wide ([Fig. 91] and G, [Fig. 92]), and are whittled down to a scant half an inch ([Fig. 93]). Green wood is generally used, and before it has had any time to season. The ribs may be softened by pouring hot water on them, and should be bent in pairs to prevent breaking ([Fig. 90]). They are held in shape by a band of cedar bark passed around outside.
The ribs are of importance in the shaping of the canoe. The sides bulge out ([Figs. 91], [92]). The shape of the ribs determines the depth and stability of the canoe.