198 Proceedings of the Royal Physical Society. 



Company erected smelting works about a mile east of the 

 mine, and produced, between 1768 and 1790, 1678 tons of 

 lead from 3685 tons of ore, which thus gave a yield of 45 

 per cent. 



After the time of this Company mining was carried on 

 intermittently till 1858, when the mine was taken in hand 

 by the late Marquis of Breadalbane and carried on till his 

 death in 1862, when all mining operations on the estate were 

 discontinued by the trustees. 



The first companies worked the highest portion of the vein 

 where it was found to be richest, taking out the best and 

 leaving the poorer ore, or using it as packing. As no roUe 

 for crushing the ore were used till the time of the Scots 

 Mining Company, a considerable quantity of good stuff was 

 lost by the previous lessees. 



The mines have all been worked by levels as shown on 

 the small section. Fig. 3. These were generally 4 feet wide 

 and 6 feet high, and several of them are still open, but a 

 good many are choked up at the mouth by the falling in 

 of rubbish from above. The ore was removed by the usual 

 method of overhand stoping, but occasionally underhand 

 stoping was also resorted to. The tough quartzite formed a 

 strong hanging wall, and in many cases large parts of the 

 vein were removed and no support left for the roof, so that 

 a black gaping chasm is now to be seen inside the hill be- 

 tween the different levels. 



In the main workings, the lowest Water or MacDougall 

 Level was laid with hutch rails the whole distance in to the 

 face. The ore was thrown down shoots from the upper work- 

 ings to this level, where it was run out to the mouth and let 

 down to the bottom of the hill by a self-acting inclined plane, 

 whence it was conveyed along a tramway to the stamps and 

 smelting works about a mile distant. 



6. Remarks. — The Tyndrum veins are all typical examples 

 of what von Groddeck, in his valuable work on Ore Deposits,^ 

 has named the " Clausthal Type," from the mining town 

 of Clausthal on the Upper Harz in Prussia. The veins be- 



1 Die Lehre von den Lagerstiitten der Erze (Leipzig, 1879), § 111. 



