GEOLOGICAL SOCIETY. 153 



tible quantity, although the quantities of earth used 

 were very small. 



The appearance of the vein in the openings 3 and 4 

 upon the plan, was such as is shown in fig. 2 of the an- 

 nexed plans, which is a transverse section of the vein 

 when looking towards the north-east, thus showing that 

 the load at these points, between the two extreme walls 

 of talcose slate, may be considered as nearly ten feet 

 wide, although its hard central quartoze part is but 

 three feet. 



It may be observed here, that although these small 

 shafts have only been sunk to the depth of seventeen 

 feet below the surface of the soil, that this is the deepest 

 part of the mine that has been explored, because the 

 fissures and crowns of the veins appear to preserve a 

 nearly horizontal direction, notwithstanding the hilly 

 and unequal surface of the ground ; and consequently 

 although the shaft on the top of the hill is forty-one feet 

 deep, yet as that hill cannot be estimated at a smaller 

 elevation than about forty -live feet above the top of 

 these shafts, which being respectively sixteen and seven- 

 teen feet deep, it will appear that the deep summit 

 shaft, No. 10, must descend at least twenty feet deeper 

 than it now is in order to reach the vein at the same 

 level as in the above excavations, as will appear from an 

 inspection of the rough eye section of the country in the 

 longitudinal direction of the vein, as hereunto annexed 

 in fig. 3 of the plans. 



The appearance of the vein in transverse section as 



it is seen when looking towards the north-east in the 

 Vol. I.— U 



