The Breadalhane Mines. 189 



sides, are arranged in a sort of imbricated pavement already. 

 But there are one or two details of their structure that do 

 not quite so well consort with this explanation. 



There is another kind of linear arrangement with which I 

 may suggest that the pavement-boulders have occasionally 

 something to do. I refer to certain of the drums or drumlins. 

 It has often puzzled me how, in an open country, where there 

 are no bosses of rock, these long drift ridges can have come 

 into existence. It is easy to conceive, however, of the lodg- 

 ment of groups of boulders, having the familiar arrangement 

 suited to resist further transport, which should afford shelter 

 to tails of drift, as the chance grains under a house-painter's 

 brush give shelter to little tails of paint ; and that with this 

 beginning a sort of composite roclies moutonn4es should be 

 gradually built up, each more or less faced with pavement- 

 boulders. The suggestion may at least be made. 



.XVII. The Breadalhane Mines. By James S. Grant Wilson, 

 Esq., H.M. Geological Survey of Scotland, and H. 

 MouBRAY Cadell, Esq., B.Sc, H.M. Geological Survey 

 of Scotland.! [Plates VII. and VIII.] 



(Read 19th March 1884.) 

 CONTENTS. 



iNTRODrCTION. 



I. The Lead Mines of Tyndktjm. 



1, Geological Structure of the Ground. 2. Geometrical Relations 

 of the Tyndrum and Coninish Veins. 3. Distribution of Ores. 



4. Composition of Veins — (1 ) Ores and (2) Veinstones. 5. Mining 

 History. 6. Remarks on the Generic Characters of the Deposit. 



n. Chrome Iron Ore of Corrycharmaig. 

 IIL Copper Mine of Tomnadashan. 



1. Topography. 2. Geology. 3. Distribution of Ores. 4. Ores, etc. 



5. Commercial Considerations, 6. Remarks on IL and III. 

 IV. Argentiferous Galena Mine of Corrie Bui. 



V. Galena and Blende Veins at Ardtalnaig. 



Intkoduction. 



We propose to give in the following pages a short account 

 of the metal mines in the district of Breadalhane, in Perth- 



^ Communicated by permission of the Director-General of the Geological 

 Survey. 



