HOLMES] THE PINY BRANCH QUARRIES 49 



under unaltered gravels at a depth of 13 feet («, figure 8), and it is thus 

 seen that in such a cutting the detection of the true conditions might 

 be next to imxjossible without careful and extensive excavation. 



THE FOURTH AND PIFTII TUFINCHES 



A number of trenches were opened about the southwestern point of 

 the promontory as indicated on the maj). It was exjiected that these 

 would throw light on various peculiar features of the topography, and 

 also add to the information regarding quarrying and manufacture. 

 The results are all that could be desired. 



The fourth trench was opened on the rounded point of the promon- 

 toiy 300 feet south of the first trench, while the filth was made a little 

 fartfier around toward the east. The phenomena observed in these 

 trenches were so nearly identical that i shall omit detailed mention 

 save of the latter and more iTiterestiug. 



The fifth trench furnished much of the evidence necessary to com- 

 plete the story of the ancient quarries. The general conditions were 

 uniform with those revealed in the first trench. At the thirtyfifth foot 

 a pocket of shop refuse of unusual interest was encountered. As 

 exposed by the trench (plate xvi) it was i or o feet in horizontal 

 extent and perhaps 3 feet deep, and its upper surface was 2 or 3 feet 

 beneath the surface of the ground. No part of the quarries, 30 feet 

 across (measured on the slope) and from (5 to 9 feet deep, was entirely 

 free from flakes and flaked stones, but the work of shaping had been 

 carried on most extensively on this one spot. From the deposit upward 

 of 40 blades, broken near the finishing stage, were recovered, though 

 the search made was by no means exhaustive; fully one-fourth of the 

 shaped pieces remained in the excavated debris. This pocket of refuse 

 was not essentially difl'erent in any of its features from those encoun- 

 tered in the first trench, but it had somewhat more the appearance of 

 a trimming or finishing shop than any yet seen. There were few large 

 or rude pieces and the flakes averaged small ; still no traces were found 

 of specialized shapes, or even of well trimmed edges or points. The 

 highest form made was a roughed-out blade such as a majority of 

 those found in caches. 



The most interesting feature of this trench was its quarry face, which 

 was encountered at about the fm-tieth foot. It was discovered that 

 extensive undercutting had been done by the ancient quarrymen, and, 

 as we advanced, the overhanging face was found to extend forward 

 several feet, as shown in plate xvi. The phenomena of this quarry 

 face are instructive in one important direction. They reveal, with more 

 than usual clearness, a favorite method of the ancient quarrymen. 

 The massive bowlder bed all around this promontory had been depos- 

 ited on the gneiss. Entering the face of the bluff on the surface of 

 this rock, rendered friable by decay, the overplaced stratum of com- 

 pacted bowlders and sand was undermined, so that the quarrying of 

 15 ETH 4 



