4 Mr. Weaver on the Gold-workings 



the elongated garnet dodecahedron, of which I retain speci- 

 mens. 



" 3. The ascertained fact that several of the contemporaneous 

 veins of quartz, contained in the mountain, were metalliferous, 

 yielding magnetic ironstone, iron pyrites, copper pyrites, 

 blende and iron ochre, with chlorite and quartz crystals. 



" Under these considerations, the measures proposed by the 

 directors were : to continue the stream-works, progressively 

 advancing toward the head of the several streams; to examine 

 more closely the solid mass of the mountain, by means of 

 trenches to be cut in various directions down to the firm rock ; 

 to explore more fully the veins already known, and those 

 which might be discovered near the surface by the trenches; 

 and lastly, to try these veins, at a considerable depth from the 

 surface, by means of a gallery or level, to be driven into the 

 mountain, in a direction nearly at right angles with the ge- 

 neral range of the veins, selecting that quarter where they ap- 

 peared to be most numerous. 



" These measures receiving the sanction of Government, they 

 were carried into effect; and numerous trials were made by 

 driving and sinking on the veins previously known and 

 subsequently discovered. By the Ballinvalley trench alone 

 twenty-seven veins of quartz were found, varying from nine 

 inches to four feet wide, in a distance of 700 fathoms ; and 

 in the same manner, by the Ballinagore trench, eighteen 

 quartz veins were discovered in a distance of 600 fathoms. 

 These veins partly range and dip with the slaty rock, but they 

 also ramify and terminate in strings which intersect the latter. 

 They are evidently contemporaneous, and most of them are 

 barren, but some were found bearing magnetic ironstone, iron 

 pyrites, and iron ochre, with chlorite. Two of the most power- 

 ful veins occur on the western side of the northern arm of the 

 mountain, one being six feet wide in the broadest part, and 

 the other four feet. They consist principally of massive mag- 

 netic ironstone and quartz, with disseminated copper pyrites, 

 and iron pyrites. A similar vein, four or five feet wide, 

 with the addition of blende, occurs near the extremit}' of the 

 northern arm, and another, two and a half feet wide, appears 

 in the face of the rock over the Daragh river." In the Geo- 

 logical Map of Croghan Kinshela mountain *, it may be seen 

 that the level driven into the* mountain, nearly at right angles 



* See Plate XI. of the 5th volume of the Geological Transactions. That 

 Map serves not only to elucidate the geological relations of the mountain, 

 but also to explain the nature of the mining operations which were car- 

 ried on there ; the whole being laid down from actual survey. 



