I860.] THOST BREADALBANE MINES. 427 



different times; and records tell that they have been extensively 

 worked for more than a hundred years. As an evidence thereof, 

 it may be mentioned that a sinking on the main vein had been cut 

 out, measuring 350 feet in length and 72 feet in depth, thus form- 

 ing an underground lake which was tapped only some months ago, 

 whereby the richer part of the ore-field became accessible. 



About half a mile from those veins a powerful quartz-vein, of 

 nearly the same bearings, attracts attention. It stands out like a 

 parapet, running for a great distance over declivities and eminences ; 

 and it has produced great changes in the adjacent strata. It may 

 be observed that its influence has towards the east been veiy sud- 

 denly and distinctly stopped at the fissure of the second vein ; but it 

 is more difficult to define that influence in the western direction, 

 where the alteration of the rock appears to die gradually away. 

 The stratum at this place consists chiefly of granular quartz, inter- 

 mixed with much felspar, and with minute scales of mica, together 

 with small specks of iron-pyrites. The strata on the east and west 

 walls of the quartz-vein have been altered from a horizontal posi- 

 tion to considerable though variable inclinations with various con- 

 tortions. Its width is often more than 4 feet, in which case the 

 quartz is quite compact and pure. When the vein is smaller, a 

 tendency towards crystallization begins, and at the same time traces 

 of lead- ore appear. Not only at the very top of the hill, where the 

 quartz-vein intersects the rock, but also at its foot in the valley of 

 Glenlochy, hollows filled with water have been formed, almost as if 

 to verify beyond doubt the theory of elevation and sinking. The 

 former lake is situated at an elevation of about 1500 feet, and the 

 latter, Lochnabuic, at about 800 feet above the sea-level. This 

 quartz-vein, though here and there not outcropping, is traceable for 

 about ten miles. 



Southern Slope of Glenlochy . — At the opposite (the southern) 

 slope of the valley of Glenlochy many more such quartz-veins, of 

 similar structure and producing similar appearances, intersect the 

 east-and-westerly course of the mountain-ridge. Among them, one 

 is distinguished by being loaded with more minerals than the real ; 

 so that it forms almost a middle member between the two perfect 

 lead-ore veins and the ban-en quartz-veins. 



Igneous Rods at Tynd/rwn. — In the neighbourhood of the district 

 under consideration only a few traces of intersecting rocks have 

 been found. These traces relate to syenite and greenstone, dose 

 to the bridge of the village near Tyndrum a trap-vein intersects the 

 mica-schist; its width is 40 feet, It may be mentioned thai iron-* 

 pyrites is of the most frequent occurrence in all parts of the district. 



Conclusion. — The foregoing remarks on this mountainous country 

 afford proofs that a great variety of minerals, mostly as regular 



formations, may be found, — and that, too, in nearly all partfl which 



have been or could be examined. By far the most disooveriee have 

 been made by the Marquess of Breadalbane, who, bj bis attachment 

 to geological resenrehes mid to the exploration of useful minerals, 

 beeame the discoverer of the silver- and copper-mines at Loch Tay. 



