When it was deemed necessary to build a canoe, certain warriors were to search out and obtain the necessary materials in the order required for construction. To do this effectively, they had to know the materials in order of their suitability for a given purpose, for the most desirable material might not be available at the building site. Other warriors prepared the materials for construction, scraping the bark, making thongs, and rough-shaping the wood. Others built the canoe, cutting and sewing the bark, and shaping and lashing the woodwork. These duties, too, required intimate knowledge of the different materials that could be used in canoe construction. It would be natural, of course, to find that the methods used to construct a temporary craft for a war-party would also be employed at home by the hunter or fisherman, even when a rather more permanent canoe was desired. These were smaller craft and easily built. Only when a long-lasting watercraft was desired would the bark canoe be unsatisfactory; then the dugout could be built. The early French observers agree that though the Iroquois occasionally used birch-bark canoes, these were acquired from their neighbors by barter or capture and were not built by the tribesmen of the Confederation. The details of the construction of elm canoes (and of other bark than birch) by the Iroquois are speculative, since no bark canoe of their construction has been preserved. This reconstruction of their methods is, therefore, based upon the incomplete accounts of early writers and upon what has been discovered about the construction of spruce-and elm-bark temporary canoes by other Eastern Indians. In view of what has been reported, it must be kept in mind that the construction was hasty and that a minimum of labor and time was employed; hence, the appearance of the elm-bark canoe of an Iroquois war-party had none of the gracefulness that is supposed to mark the traditional war canoe of the Indians. The ends are known to have been "square," that is, straight in profile, and the freeboard low. The use of saplings for the gunwales would cause an uneven sheer, and its amount must have been small; the high, graceful ends seen in some birch-bark canoes did not exist in the Iroquois model. The rocker of the bottom profile was not a fair curve, but was angular, made of straight lines breaking under the folds, or "crimps," in the bark cover at the gunwales. The amount of bark in each crimp and the location of the crimps fore-and-aft would determine the shape of the bottom profile and the amount of rocker, as well as the flatness of the bottom athwartships in the midbody. It appears that two crimps to the side were employed in most of these canoes, but perhaps more, say four to a side, might have been employed in a very large canoe. The tendency in forming these canoes must have been toward an almost semicircular midsection, a condition which would have produced an unstable craft if not checked.