(>\ THE SHORES o F LAKE SUPERIOE 15 



They are partly upon the land of the Quincy Mining Company and in part on 

 the Pewabic, a short distance- cast of the landing, as shown in the sketch. Those 

 constituting the upper series are even, broad, deep, and regular, having the appear- 

 ance of old fortifications. Thej extend around the headlands of gravel, connecting 



adjacent ravines, as though the object was to bring water from the- rivulets along 

 the face of the bluff. 



At the points of the ridges they are much broader and deeper than they are at 

 the heads of the ravines. The resemblance to a race way, or "sluice" for running 

 water, is such that it required much examination to convince me that they had 

 not been used for that purpose. There are, however, no openings at the extremi- 

 ties, such as would have been the case in sluices, to admit and discharge water. 

 A bench, or narrow terrace, breaking into the slope of the hill, forms a regular 

 plateau for the uppermost group ; the other groups being scattered along the slope 

 at irregular intervals. Some of them extend down the declivity nearly to the 

 water's edge. Pits of a peculiar shape are occasionally seen to the westward of 

 the landing, particularly at the distance of about a mile. Here is a group of small 

 ones covering several acres on a piece of level land, which is elevated about 200 

 feet above the lake, constituting one of the upper drift terraces. 



There arc no doubt many others, large and small, concealed by the thick brush 

 wood with which the ground is covered. Mr. ('. ('. Douglass, formerly an assistant 

 of Dr. Houghton, in the geological survey of the Upper Peninsula, and since for 

 many years the superintendent of the Quincy and Isle Royale Mining Companies, 

 states that lumps of water-rolled copper and small masses are frequently found on 

 both sides cf the lake in this drift gravel. In digging cellars, constructing roads, 

 and exploring trenches, such pieces are so common, that it has been thought that 

 they would pay for their collection by washing the earth. One mass of 1500 

 pounds weight was found in digging a cellar where there is no rock visible in place. 



To obtain this transported mineral, Mr. Douglass conjectures to have been the 

 object which the ancients pursued in their gravel trenches, and at the same time, 

 that they selected from the water-worn boulders of the coarse drift such stones us 

 had the proper size and shape for mauls, to be used in the adjacent rock excava- 

 tions. 



The earth from the trenches near the landing, on the slopes, was principally 

 thrown out over the lower side, forming embankments with an extreme height of 

 fifteen feet above the bottom of the ditch as it remains now after the lapse of 

 centuries. 



Some of the ditches are fifty feet wide at the present time. 



The beds of trap, constituting the mineral range, at this place, have a total 

 thickness of about a mile and a half, presenting the ends of the strata towards 

 the lake. To reach the rock excavation of the ancients, it is necessary to follow 

 a road from the landing up the mountain three-quarters of a mile to the north- 

 east. Here the copper bearing rocks protrude from the soil in ledges ; the 

 intervals where no rock is seen being covered to a slight depth with earth. 

 The veins of this part of the range have a direction different from those before 

 described on Point Keweenaw. They have run with the formation, and not at 



