According to early accounts and the statements of eastern Indians, these emergency canoes were often heavy and unsuitable for portaging. By 1750, at least, the Iroquois were using blanket square-sails in their elm-bark canoes. _Skin Boats_ Among the other forms of temporary or emergency canoes used by North American Indians, the most widespread was some form of skin boat. These would not require description here were it not for the fact that the Indian skin boats were usually built by bark-canoe methods of construction rather than by methods such as used by the Eskimo. To build their skin boats--kayaks and umiaks--the Eskimo first constructed a complete framework, and this was then covered with skins sewn to fit. This process of building required a rigid framework capable of not only standing without a skin covering but also of giving both longitudinal and transverse strength sufficient to withstand loading, without the slightest support from the skin covering. Hence, the framework of the Eskimo craft was made with the members rigidly lashed and pegged together. The majority of Indian skin canoes, however, required the covering to hold the framework together, as in a birch-bark canoe. An example is the Malecite skin-covered hunters' canoe. According to available information, the Malecite hunter would leave two or three moose skins on stretchers for use in building a skin canoe in the early spring. Sometimes the hair was removed from the hides and sometimes it was not. Spare time during the winter hunt might be spent in preparing the wooden framework, but if this were not done the delay would not be very great. The gunwale frame was first made of four small sapling poles roughly scarfed at the butts. From a small sapling a middle thwart was made in the manner of the elm-bark canoe thwarts, the ends tapered enough to allow them to be wrapped around the gunwales and secured under the thwart by lashings. The ends of the gunwales were merely crossed and lashed. Where end thwarts would be placed, it was usual to use a cross tie made of twisted rawhide or cords of bark fiber. Holes were then drilled at intervals in the underside of the gunwale to take the heads of the ribs. Stem-pieces about 3 feet long were prepared of short saplings and bent to the desired profile; one builder used a full-length keel-piece, instead of the short stem-pieces. The ribs were usually of small saplings that could be bent green without the use of hot water. For sheathing a number of small saplings were also gathered, and from them were made poles in lengths about equal to three-quarters, or a little more, of the intended length of the canoe, which would be determined by the size of the skins available. The average canoe was about 12½ feet long, roughly 40 inches beam, and 14 to 19 inches in depth.