42 STONE IMPLEMENTS (eth.ann.is 



soil of the surt'iutc was lillcd witli nho[> leluse, most of which has not 

 been far removed from the si)ot of manufacture. The cross sections are 

 too limited in extent to show clearly the bedding of the aecumnlatious, 

 but they serve to ilhistrate the nature of the contents of tiie jiits. 



The conditions at tiie fortyfoiirtli foot are given in (h) plate Vii. Jiy 

 carryinj;- the excavation to the riyht and left the outlines of the old 

 dei)ressions were found to be irregular and extended so far that I did 

 not undertake to define them fully. It appeared, however, that our 

 section had cut the deepest i»art of this particular depression. A pho- 

 tograph covering the rectangular space outlined by a dotted line in the 

 section is reproduced in plate viii. I am fortunate in being able to 

 present such an illustration of the composition of the refuse at this 

 point, as it affords evidence that can not be gainsaid, and the student 

 may study the nature, conditions, and relations of the component i)arts 

 with ease. The picture covers a space about 2 feet wide by 3 high, 

 the top being 2.^ feet below the surface of the ground and the bottom 

 within a few inches of the deepest part of the ancient excavation. The 

 unusual number of large bowlders is a notable feature, but it will be 

 found that the broken and worked ones far outnumber the unbroken, 

 and that several partially shaped tools are in sight, occupying positions 

 no doubt very much the same as when dropped by the workman. A 

 turtleback appears near the base beneath the large split bowlder; others 

 are seen to the left and a little higher, while numbers are seen to be 

 dropping out of the loose, open mass of refuse near the middle of the 

 picture. The section abounds throughout with artificial material. 



After passing the fiftieth foot the deposits exhibited the usual phe- 

 nomena, and no features of exceptional interest were encountered until 

 the seventieth foot was reached. The bottom of the old pits continued 

 at about the same level, so that the artificial deposits became gradually 

 deeper as we advanced. Occasionally small masses of the Potomac 

 gravel (small bowlders anil pebbles held together by an indurated sand 

 matrix) were encountered, indicating the proximity of the ancient 

 quarry face. The pitting had been carried down almost to the gneiss 

 floor, which was here nearly level, being covered with a bed of sharp 

 yellow sand from an inch to a foot thick. It was afterward ascer- 

 tained that this layer of sand formed a part of the original Potomac 

 dejiosits and separated the gneisses from the beds of bowlders above, 

 as shown in the section. The artificial deposits, about 7 feet deep at 

 the sixtieth foot, deepened to 10 or 11 feet at the quarry face 20 feet 

 farther on. 



Between the fiftieth foot and the sixtieth the refuse was distributed 

 in alternating beds of gravelly earth and shop deposits, as shown in 

 the general section. These beds constituted the refuse derived from 

 extensive operations along the quarry face. After passing the seven- 

 tieth foot the layers of refuse were inclined toward the quarry face, as 

 indicated in the section. 



