The adz was in general use long before the introduction of iron. There is in the collection a very interesting series of ancient tools, showing the gradual development of the implement from a rude oblong block of stone worked down to a cutting edge on one end, to the steel adzes of the present day. They have, however, not even yet learned to make an eye in the head of the tool in which to insert the haft, but all tools of this class--adzes, hammers, picks, and mattocks--are lashed, with one face resting against the expanded end of the haft. Firmness is obtained by putting the lashing on wet and allowing it to shrink tight. Nearly all these ancient adzes are of jade, a material well adapted for the purpose by its hardness, which, however, renders it difficult to work. Probably the oldest of these adzes is No. 56675 [69], Fig. 130, which has been selected as the type of the earliest form we have represented in the collection. This is of dark olive green, almost black, jade, 7.2 inches long, 2.8 wide, and 1.3 thick, and smoothly ground on the broader faces. The cutting edge is much broken from long use. One broad face is pretty smoothly ground, but left rough at the butt end. The other is rather flatter, but more than half of it is irregularly concave, the natural inequalities being hardly touched by grinding. Like the other dark-colored jade tools, this specimen is very much lighter on a freshly fractured surface. The dark color is believed to be due to long contact with greasy substances. [Illustration: FIG. 130.--Adz-head of jade. 1/3] [Illustration: FIG. 131.--Adz-head of jade. 1/3] No. 89662 [900], from Nuwŭk, is an exceedingly rough adz of similar shape, but so slightly ground that it is probably one that was laid aside unfinished. From the battered appearance of the ends it seems to have been used for a hammer. It is of the same dark jade as the preceding. No. 89689 [792], from Utkiavwĭñ, is of rather light olive, opaque jade and a trifle better finished than the type, while No. 89661 [1155], Fig. 131, also from Utkiavwĭñ, is a still better piece of workmanship, the curve of the faces to the cutting edge being very graceful. The interesting point about this specimen is that a straight piece has been cut off from one side by sawing down smoothly from each face almost to the middle and breaking the piece off. We were informed that this was done to procure rods of jade for making knife sharpeners. We were informed that these stones were cut in the same way as marble and freestone are cut with us, namely, by sawing with a flat blade of iron and sand and water. A thin lamina of hard bone was probably used before the introduction of iron. Possibly a reindeer scapula, cut like the one made into a saw (No. 89476 [1206], Fig. 147), but without teeth, was used for this purpose. [Illustration: FIG. 132.--Hafted jade adz. 1/2]