IN SOUTII-EASTERIsr PEXNSYLVAXIA. 



353 



has the form and edge roughl}'' shaped h}^ a few blows (Fig. 15, 17) ; the third 

 variety inchides such as have an edge formed by fine chipping, as in Fig. 4, the left 

 side of which is a cutting edge, and the base a scraper ; Fig. 5, delicately chipped on 

 one side, the other flaked into a bevel at the same angle ; and Fig. 14, with a cutting 

 and scraping base, the edge transversely curvilinear. (Figures 13-17 represent 

 specimens made of white quartz.) The fourth variety is made up of flakes struck 

 from a hard material, such as porphyry (Fig. 1, 11), trap (Fig. 3), indurated clay* 

 (Figs. 6, 7, 8), jasper (Figs. 4, 9), or cherty limestone (Fig 5). Finail}^, the fifth 

 variety is due to rubbing or grinding (PI. 2, Fig. 4), and polishing (PI. 2, Fig. 8). 



As the rock of the locality is a dense quartzite with occasional large veins of 

 white quartz, any unworked specimen of either, occuriing in the Retreat, might be 

 due to a fall from above, or other accident, even after the inhabitants had left, and on 

 this account I have collected but few of such doubtful specimens. On the other 

 hand, as thei-e is no sign of a drift deposit in the retreat (except perhaps the unmixed 

 yellow sandy clay of the foundation), human occupants must have introduced stones 

 of other material, such as indurite, jasper, sandstone, chert, siliceous slate (Fig. 12), 

 and limestone, the last being vicinal, but as it does not take a good edge, it was not 

 much used. 



The sharp edges of the examples figured indicate that they were knives ; the 

 obtuse and transversely curvilinear edges indicate scrapers; Figs. 1, 2, 3, seem to 

 have been pointed for the additional function of boring ; and the grayish-white quartz 

 specimen Fig. 13, 13a, has been carefully chipped into a concavo-convex form 

 narrowing to a lateral point ; with an edge on each side, constituting a kind of knife 

 (perhaps used with a handle), the curvature of which suggests that it was a skinner. 

 Compare Evans, Stone Implements, p. 317, Fig. 268. 



In the knife, Fig. 12, the inferior or convex margin forms the edge, which con- 

 tinues to the narrower end, the upper, concave margin being obtuse, and at right 

 angles with the sides : material gritty slate. 



The bur which often appears at the point where a sudden blow is given in 

 breaking olf a flake, is seen at the upper or narrow end in Fig. 10; and curved forms 

 from the same cause appear in the trap specimen, Fig. 3, in the porphyritic specimen. 

 Fig. 11 (a point of which I have polished to exhibit the material), and in the indurite 

 (indui-ated clay), examples Figs. 6, 7, 8.t The last mentioned material pertains to 

 the Di-ift, and came from the Conewago Hills ten miles north. The name indurated 



*For convenience, this rock will be called indurite in these pages. It will include baked (but not vitrified) clays, 

 often due to the vicinity of trap masses, and usually hard enough to scratch glass. 



fSee Lulibock, Prehistoric Times, p. 85-89, on similar forms, and the mode of making them in Australia. 



