Bark canoes developed in a few areas, ranging in design from craft having only the most elementary framing to the highly developed of the The birchbark canoes had framing of ribs forced under the gunwale. So efficient were yate santa marta these canoes that copied them for wilderness travel. Skin craft range from inflated skins, used singly or joined together in a raft, to framed hulls of good form and construction. In the latter there is a rigid frame composed of longitudinals and ribs secured by lashings or pegs, and the skins are The lapstrake type of planking, in which each plank or strake overlaps slightly the one below it, can be seen in an elementary form in some dugouts with plank sides. In early forms the lap is sewed its full length. The lapstrake planking method appears to have reached its final form in northern Europe, where iron fastenings were used. As seen in the remains of ancient European craft, the seams were nailed at the laps but the planking was lashed to the ribs or frames. The use of metal fastenings throughout the hull did not become common, apparently, until about the 9th century in northern Europe. Caravel planking has smooth seams, with the planks placed edge to edge and fastened only to the frames. This originated in the Mediterranean basin; possibly it evolved from the older edge-fastened plank construction of the Egyptians. However, it took its name from a class of ships built in Spain and Italy in the 14th and 15th centuries. Plank construction did not become common in Europe until metal fastenings were procurable, although pegged construction was probably used in an early stage of evolution.
The basic framework of planked boats of lapstrake forms is the same: a keel and transverse frames or ribs more or less evenly spaced along the length of the boat. At the gunwale or top edges of the planking there are longitudinals, and sometimes a little below the gunwale there are additional longitudinals to support the rowing seats or thwarts. In the early boats the frames were cut from “knees” or crooked timber, but early in the 19th century steam-bent frames came into use. One marked difference between lapstrake- and caravel-
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