74 



STOXK IMI'LKMKNTS 



[ETII. AVS. 15 



used or iuteiidi-d for use a.s an implement. altLiouj;li this is not jiioba- 

 bio. It is .shown in li<^ure 12. A much larger piece, an oblonj^ blade- 

 like inas.s, was found by Mr .1. D. McCiuirc in the Patapseo valley. 

 Such shapes are very eoinmou in the (juarries, and are often mere 

 rejects of thi' l>l;ide maker. 



For several years the source of this stone remained unknown. 

 Members of the (leoloj^iciil Survey were engaged in examining parts 

 of the Piedmont j)!ateau drained by the Potomac, and I ai)pealed to 

 them to keep a lookout for the stone. In the sumnu>r of 1801! Professor 



Fig. 12— Frajxiiu-nt of rliynlite from tht- rntoiiKu-, HI miles below W.i.shington. 



G. H. "Williams, of .lolins Ihipkins university, an assistant geologist 

 on the Survey (whose untimely death iu 1894 Avas a serious loss to 

 science), reported its occurrence in South mountain, and in the autumn 

 he and Mr Arthur Keith, of the Geological Survey, furnished me with a 

 map of the foruuitious so far as outlined at that time. The outcrops 

 exteiuled in broken narrow belts through Maryland and Pennsylvania, 

 as already mentioned. 



Early ill November, 18!)2, 1 set out in search of the quarries. Taking 

 a team at Keedysville, ^Maryland, I crossed the mountain ridge at sev- 

 eral points, lindiiig excellent outcrops of the rock at many jioints, but 

 no trace of aboriginal operations appeared until I reached Maria 



