No. 89793 [873], Fig. 206, is a typical toggle head of this kind, intended for a walrus harpoon (túkɐ), and will be described in full, as the names of the different parts will apply to all heads of this class. The _body_ is a conoidal piece, 4½ inches in length, and flattened laterally so that at the widest part it is 1 inch wide and 0.7 thick. On one side, which may be called the _lower_, it is cut off straight for about half the longer diameter, while the upper side is produced into a long, four-sided spur, the _barb_. The _line hole_ is a round hole about one-fourth inch in diameter, a little back of the middle of the body, at right angles to its longer diameter. From this, on each side, run shallow _line grooves_ to the base of the body, gradually deepening as they run into the line hole. In the middle of the base of the body is the deep, cup-shaped _shaft-socket_, which fits the conical tip of the shaft or fore shaft. In the tip of the body is cut, at right angles to the longer diameter of the body, and therefore at right angles to the plane of the barb, the narrow _blade slit_, 1.1 inches deep, into which fits, secured by a single median rivet of whalebone, the flat, thin _blade_ of metal (brass in this case). This is triangular, with curved edges, narrowly beveled on both faces, and is 1.9 inches long and 1 broad. [Illustration: FIG. 207.--Harpoon head. 1/3] The body is sometimes cut into faces so as to be hexagonal instead of elliptical in section as in Fig. 207 (No. 89791 [873]), and intermediate forms are common. When such a head is mounted for use a bight of the line or _leader_, a short line for connecting the head with the main line, runs through the line hole so that the head is slung in a loop in the end of the line. The tip of the shaft is then fitted into the shaft socket and the line brought down the shaft with the parts of the loop on each side resting in the line grooves and is made fast, usually so that a slight pull will detach it from the shaft. When the animal is struck the blade cuts a wound large enough to allow the head to pass in beyond the barb. The struggles of the animal make the head slip off the tip of the shaft and the strain on the line immediately toggles it across the wound. The toggle head of the whale harpoon is called kia¢ron, of the walrus harpoon, tukɐ, and of the seal harpoon, naulɐ. They are all of essentially the same pattern, differing chiefly in size. [Illustration: FIG. 208.--Ancient bone harpoon head.]