142 Mr. Williams's account of the 



spersed a little yellow copper ore, accompanied by quartz, chlorite 

 and iron pyrites to a considerable depth. Both the tin and copper 

 veins have been traced for about a mile in length. 



The two slides which run parallel with the metalliferous veins 

 afforded no trace of either copper or tin. The northernmost 

 of the two is from 4 to 12 inches wide; the southernmost from 2 to 

 3 inches. They were found to consist wholly of an argillaceous 

 clay, called by the miner flucan. These veins, as will hereafter be 

 seen, notwithstanding their poverty, were one principal cause of 

 the remarkable incidents attending this mine. 



It will be seen by the ground plan that the eastern cross course at, 

 (which was about 4 feet wide, consisting of 3j feet of quartz on the 

 western side, and 6 inches of flucan on the eastern,) traversed the 

 channel of porphyry, the tin and copper veins, as well as the two 

 slides, heaving them all 54 fathoms to the north on its western side, 

 where they maintain the same distance from one another as on the 

 eastern side. The cross vein y next on the west, which consisted of 

 the same substances as the cross vein #, and on the surface where it 

 cut the tin vein at P was distant from it only about 26 fathoms, had 

 precisely the same effect on all the east and west veins, except that 

 the distance of the heave north was only 18 fathoms, so that the tin 

 vein, at its place of contact with the west side of the cross vein y at 

 P was exactly 72 fathoms north of that part of it in contact with 

 the eastern side of the cross vein x at Q. Of the cross vein at 

 the western extremity of the mine, (as has before been noticed) little 

 is known. But the two former have been traced nearly five miles 

 in length intersecting every tin and copper vein, and from every 

 observation, it seems probable that they extend from the Bristol to 

 St. George's Channel, and are very distinctly seen in the cliffs near 

 Porthtowan on the northern coast. 



