HOLMES] THE DUMBARTON HEIGHTS (^)UARRY 65 



particular interest was encountered. The mass, to a depth gradually 

 increasing to 8 feet as we advaueed, consisted of earth and gravel, 

 intermingled with shop refuse. This rested on the uneven Moor of the 

 old quarry, composed of the undisturbed, tirmly compacted bowlder- 

 bearing gravels. The ancient workmen rarely penetrated, save on the 

 outer margins of the quarry, to the gneiss bed. 



At the fortyfifth foot a pocket of refuse, containing broken bowlders, 

 failures, broken blades, and flakes, in considerable quantities, was 

 exposed. This was at a depth of about 3 feet. Tlie conditions were 

 identical with those of the Piny branch sites as the qimrry wall was 

 approached. The characteristics of the exposures in the trenches may 

 be summed up in a few words. The quarry debris consists of a hetero- 

 geneous mass of sandy clays, sand, gravel, bowlders of quartz and 

 quartzite, and shop refuse, all well comiiacted and diflicultto penetrate 

 and remove with pick and shovel. The shoj) refuse includes broken 

 bowlders up to a foot in greatest dimension, rejects representing all 

 varieties of failures, unfinished tools broken at various stages of 

 develoi>ment, and numberless Hakes. These are generally distributed 

 throughout the mass of (juarry d(''bris, but at intervals clusters or 

 pockets were encountered, where consideral>le shaping had been done 

 at a single sitting or on a particular spot. 



The quarry face was reached at a distance of about "w feet from the 

 beginning point of the trenching. It was, at the point reached, quite 

 abrupt, being nearly vertical for about 5 feet. The full depth was 

 about 71 feet. At other points, exposed in various lateral trenches, 

 the old quarry face vras found to be very poorly defined. It would 

 appear that the ancient quarrymen did not work with any considerable 

 regularity or system. Xumerous excavations had been carried into the 

 sloping face of the hill, and had been abaiuloned near the crest. The 

 series of terminations constitute an irregularly scalloped and variously 

 inclined quarry face. A detailed description of the numerous short 

 trenches, o^jened at various points along the margin (jf the promon- 

 tory crest, need not be given. The conditions are uniform, and at no 

 point was the ancient work so extensive as where the first two trenches 

 were dug. 



In one of the side trenches a good deal of charcoal was found, and 

 at the depth of about <! feet a charred log more than 10 feet long and 

 in places a foot in diameter was encountered. It rested on or near the 

 bottom of the ancient excavation, and consisted of a shell of charcoal, 

 the interior uncharred portion having been entirely replaced by sand, 

 which had found its way through the crevices. There is no reason to 

 suppose that it was used by the ancient (|uarrymen in their work, or 

 that it was anything more than a log which, having fallen into the 

 deserted pit, was burned by forest fires. Charred wood and snnill 

 masses of charcoal were found, but man's agency was not necessarily 

 involved in their production. 

 15 ETH 5 



