“Gabbro or black granite was then used for a hammer and was found useless; gneiss proved to be no better, and the work appeared hopeless. Finally, through the kindness of Mr. Weed, of the United States Geological Survey, a rough piece of compact yellow jasper from the Yosemite was obtained, with which about forty hours’ work was done. The jasper was worn but slightly, the nephrite losing about the same weight as the jasper. This hammer is yet large enough to manufacture many dozens, if not hundreds, of such implements as the celts and axes usually found in this section of country. With a nephrite hammer of suitable shape, having a narrow periphery, the work of fashioning this axe could probably have been done in one half the time. “In the process of manufacture, owing to a flaw, a large piece of the blade was broken off and a second flaw, running diagonally through the specimen, threatened to destroy it if the hard pounding was continued. Work on it had therefore to be curtailed. The groove could not be worked deeper because the jasper hammer did not have a narrow edge. The outline having been carried as far as was thought safe, grinding on a block of rotten granite was resorted to; the granite was kept wet and the nephrite, being held in the hand, was rubbed backward and forward for about five hours. Subsequently it was polished with a pebble of compact quartzite, both dry and wet, the process occupying about six hours. The axe was then rubbed with wood and with buckskin to further polish it, but apparently without effect. The pecking occupied 55 hours and 10 minutes, which period, estimating the number of blows per minute as 140, would give over 460,000 blows required for the manufacture of the implement. This stone weighed when first received 7625 troy grains; the present weight is 5143 grains; the loss therefore is 2482 grains. This specimen, however, can hardly be taken as a fair standard of aboriginal work, for in selecting the material a workman would naturally choose a pebble as nearly the desired shape as could be procured, and thus avoid a large part of the labor. The savage, if we can believe the accounts given of him by early travelers, was not likely to make unnecessary exertion. [Illustration: FIG. 211. (S. 1–5.) Material: granite. All are from South Dakota. Collection of Mrs. Ella V. Milliken, Alpena, South Dakota. ]