After measurements have been made for the first rib with a strand of root or an ash batten, it is now cut to a length slightly more than would permit the rib to be forced upright when in place. The ends of the rib are set in place in the bevel, or notch, on the underside of the gunwales, against the bark cover, and with the bottom part of the rib standing inboard of the head. Then, with one end of a short batten placed against its inboard side, the rib is driven toward the end of the canoe with blows from a club on the head of the batten. If the rib drives too easily it is removed and laid aside; if too hard, it is shortened. It must go home tightly enough to stretch slightly the bark cover by bringing pressure to bear on the whole width of the sheathing. Care is taken, in this operation, to keep moist not only the bark but also the sewing, particularly along the gunwales, so that all possible elasticity is obtained. The ribs are set, one by one, working to within two or three frames of the midship thwart; then the other end of the canoe is begun. The last three or four ribs to be placed are thus amidships. In every rib driven, the tension is great, but no rib is driven so that it stands perpendicular to the base. Those first driven stand with their bottoms nearer the midship thwart than the ends, and this angle, or slant, continues to amidships; the ribs in the other end of the canoe slant in the opposite direction. It will be evident that skill is required to estimate how much pressure the bark will stand before bursting under the strain of the driven ribs. It is also apparent that the shape of the canoe is controlled by the shaping given the ribs in the prebending, for this fixes the amount of tumble-home and the amount of round, or rounded-~V~, given to the bottom athwartships. No fixed rules appear to exist; the eye and judgment of the builder are his only guides. To show how much strain is placed on the bark, however, it may be noted that inspection of two old canoes showed that the gunwale pegs had been noticeably bent between the inner and outer gunwales. It appears to have been a rather common practice, after all the ribs had been driven into place, to allow the canoe to stand a few days and then again to set the frames (where unevenness appears in the topsides) with driving batten and maul, the bark cover and the root sewing or lashings having been again thoroughly wetted.