Lesley.] 476 [December. 



Mountain and the Main Mountain at the Pond-banks (or rather at 

 the English openings; see the map, Plate IX). The anticlinal axis is 

 no doubt that of the Little Mountain itself, which brings up the slates 

 on the back of the Pottsdam sandstone, and thus produces the grand 

 exhibitions of ore all around it, as shown in Fig. 4. 



The Pond-banks and Caledonia-bank, and the English diggings, 

 are several openings of greater or less size in the upturned belt 

 of slates surrounding the Little Mountain, which rises as an iso- 

 lated ridge, one or two miles long, from the floor of the valley. 

 The English diggings are behind it, the Caledonia-bank before it, 

 and the Pond-banks at its south end, in the plain. The ore mass in 

 the Caledonia-bank dips 5° towards the mountain, but must cer- 

 tainly rise again upon its flank. The English ore evidently dips 

 10° — IS** away from the mountain. The difliculty of estimating the 

 quantity of ore on this ground is very great, on account of the enor- 

 mous covering of red earth upon it in places. The shape of this 

 deep excavation is that of a crescent, with nearly vertical sides, and 

 an irregular bottom.* Its whole length is about three hundred yards, 

 and its depth to the general floor is from 60 to 80 feet. The ore 

 appears within 10 to 20 feet of the surface, at some points, and at 

 others not for 30 or 40 feet down. Mountains of stripping stand 

 beside it to the west, above where the body of the ore turns over a 

 small anticlinal, and buries itself westward beneath undecomposed 

 limestone. The depth of the ore is still unknown. Shafts from 60 

 to 110 feet have been sunk in it at the sides and in the bottom of 

 the present excavation. The top of the ore stratum at the extreme 

 north end of the quarry is exactly on a level with the edge of the 

 upper Pond-bank, which is only 5 or 10 feet above the top of its own 

 ore, into which the mining has descended 30 to 40 feet. The lower 

 Pond-bank is on a slightly higher level. 



The fact is, therefore, that all these three excavations, separated 

 by only one or two hundred yards of interval from each other, and 

 extending in a line about one thousand yards, are sunk in one de- 

 posit of ore ; or, to speak more correctly, in the broad overlapping 

 margin of the ore-bearing slate deposit, which sweeps round the 

 south end of the Little Mountain in a nearly horizontal and partly 

 basin-shaped posture. 



In the bottom of these excavations the ore is reported as uniformly 

 well compacted. In the upper end (north end) of the Caledonia- 



* The sketch Fig. S, Plate X, was made from the head of the road. 



