“Some may doubt whether the stone hammer could do the work suggested [Mr. McGuire illustrated the truth of this contention by making an axe]. It is made of a close-grained black porphyry that in 1878 was pecked out and grooved entirely with a stone hammer by the writer as a first effort, to demonstrate the method of axe-grooving. The work on this stone represents approximately five hours’ labor. When the hardness of material is taken into consideration, it is safe to conclude that it could not have taken more than one half as much time to groove an ordinary axe, since they are of much softer material. From this may roughly be calculated the time that would be required to fashion a stone axe or in fact any other stone implement which was made by pecking and polishing; and it will be seen that, granting a liberal allowance of time, the manufacture of stone implements consumed a small portion of the time supposed to be requisite. The statement that the manufacture of an axe or in fact of any other stone implement was a long process has so often been made that it may be regarded as a common belief among archæologists. So great have the difficulties of their manufacture been supposed to be that it has been surmised even that early races had other than stone tools.” [Illustration: FIG. 208. (S. 3–4.) This may be an unfinished discoidal or “bicave,” or it may be a hammer-stone finer than the average. Hy. B. Bischoff, Collinsville, Illinois. ] The various types of hammer-stones used in chipping flint implements are shown in Chapter II, Figs. 13 and 14, of this book. In the _Anthropologist_ for April, 1892, Mr. McGuire gave an account of the manufacture of the nephrite axe. I quote from Mr. McGuire’s paper as follows:— [Illustration: FIG. 209. (S. 1–4.) Phillips Academy collection. ] [Illustration: FIG. 210. (S. 1–3.) Phillips Academy collection. The various types of grooved hammers. ] “The material of a grooved nephrite axe made by the writer is from New Zealand, and was procured through the kindness of Professor Clarke, of the United States National Museum. This stone is one of the toughest as well as of the hardest known, and when work was first commenced on it was irregular in shape as when broken from the large boulder, with sharp edges that cut the hand as the stone was struck with the hammer. In pecking with the stone hammer, about one hundred and forty blows were given to the minute. The hammers first used were of quartzite from Piney Branch, on the edge of Washington City. About forty pebbles were destroyed before one was found tough enough to stand the necessary pounding. With a single exception, none lasted more than ten minutes. The exception was a close-grained gray quartzite, with which was performed eight or ten hours’ work.