The "crooked knife" was the most important and popular steel tool found among the Indians building bark canoes. It was made from a flat steel file with one side worked down to a cutting-edge. The back of the blade thus formed was usually a little less than an eighth of an inch thick. The cutting edge was bevel-form, like that of a drawknife or chisel, with the back face quite flat. The tang of the file was fitted into a handle made of a crotched stick, to one arm of which the tang was attached, while the other projected at a slightly obtuse angle away from the back of the blade. The tang was usually held in place by being bent at its end into a slight hook and let into the handle, where it was secured with sinew lashing; wire later came into use for this lashing. The knife, held with the cutting edge toward the user, was grasped fingers-up with the thumb of the holding hand laid along the part of the handle projecting away from the user. This steadied the knife in cutting. Unlike a jackknife, the crooked knife was not used to whittle but to cut toward the user, and was, in effect, a one-hand drawknife. This form of knife is so satisfactory that it is to this day employed instead of a drawknife by many boat-builders in New Brunswick and Quebec. A variation in the crooked knife has the tip of the blade turned upward, on the flat, so that it can be used in hollowing out a wooden bowl or dish. The blades of crooked knives seen are usually about five-eighths inch wide and perhaps five or six inches long. Some are only slightly beveled along the cutting edge; others show this feature very markedly. Awls, as well as chisels and other stone or bone blades, often had handles on their sides to allow them to be held safely when hit with a hammer. Some of the stone blades and chisels thus took the form of adzes and could be used like them, but only, of course, to cut charred or very soft wood. The sharpening of stone tools followed the same methods used in their original manufacture and was a slow undertaking. To some Indians an efficient wood-cutting chisel was available in the teeth of the beaver. Each tooth was nearly a quarter inch wide, so two teeth would give a cut of nearly half an inch. The usual practice appears to have been to employ the skull as a handle, though some beaver tooth chisels had wooden handles. As used in making tenons in the gunwales, two holes, of a diameter equal to the desired width, were first drilled close enough together to make the length of the desired tenon, after which the intervening wood, especially if it was white cedar or black spruce, could be readily split out by means of either a beaver tooth or narrow stone chisel.