Ch. VIII.] THE GRANITIC AND SCHISTOSE ROCKS. 157 



granite be regarded as a heave, this also must be viewed in 

 the same light the movement, however, having been directed 

 to the opposite point of the compass ; but we find that the 

 continuation of this quartz-vein has produced no such effect 

 on the granite- vein c, being traversed by its southern, though 

 it intersects its northern branch. The quartz-vein H is par- 

 ticularly interesting. It passes through both the granite-vein 

 E, and the elvan, producing something like a heave in the 

 latter, but does not alter the course of the former: inter- 

 mediate, however, between these points, it traverses and 

 heaves, for about half a foot, a quartz-vein K, which is 

 intersected by the granite-vein, as also is the quartz-vein L, 

 which might be considered as a branch of H. Here, then, 

 we have facts for and against a motion in the strata, within 

 the space of about 50 feet. The quartz-vein M heaves both 

 the granite-veins D and E towards the north: the former 

 3 feet, the latter only about 6 inches ; the distance between 

 these veins being 30 feet : an occurrence which (as will be 

 shown hereafter) is very common among metalliferous veins. 

 The distance of the elvan, and the granite-vein E, from the 

 main mass of granite on the side of the western hill, does 

 not, perhaps, exceed 100 feet. They appear, as well as the 

 vein D, to increase in size as they recede from the granite : 

 this may be a deception ; for, as the shore dips eastward, 

 the veins may become nearer and nearer to the granite 

 beneath, as they retire from this rock at the surface. These 

 veins, in several places, can be seen in nearly a perpen- 

 dicular position, in sections which vary from 1 foot to 3 feet in 

 depth : and since the same kind of veins abounds in the 

 southern mass of granite, running in a parallel direction, it 

 is probable that a more extended section would exhibit them 

 passing through both rocks. The position, therefore, of 

 these larger veins corresponds with the perpendicular faces 

 of the aggregated concretions ; whilst the quartz-veins are 

 situated on those concretionary planes which cross these at 

 right angles, dipping rapidly towards the west. It has already 

 been stated in the last chapter, that the strike or course of 



