328 PEOCEEBINGS OF THE GEOLOGICAL SOCIETY, [JuilG 9, 



an extremely uneven face, ramifying very frequently into the country 

 and the horse (fig. 1) . With regard to its auriferous contents, the 

 eastern vein stands far behind the western in richness : although 

 the yields of gold from certain parts have been very fair, still, on 

 the average, they were low, and the character of the vein became 

 irregular in depth ; whilst the western vein contained the gold more 

 richly and evenly distributed, and showed a more regular course on 

 being followed downward. It was rarely less than 3 feet, but in- 

 creased in places to 20 feet and more in width (Crystal's Claim). 



Next southward of the Alliance Company, in the ground worked 

 by the Speculation Company, a great alteration is apparent in 

 the character of the horse separating the two veins. It becomes, 

 from the surface downward, gradually more thickly traversed by 

 quartz -strings, which are mostly auriferous, and at about 200 feet 

 in depth it represents in reality a close irregular network of quartz 

 and metamorphic sandstone. One of these strings, near the centre 

 of the ^* horse," increases to several feet in thickness, becomes well 

 defined in dip and strike, and, being also more auriferous than the 

 rest, is advantageously worked and called the " middle vein." The 

 eastern vein is in this ground not visible on the surface, and was 

 for several years, in fact, not supposed to exist, till, through some 

 workings, to be mentioned further on, and certain features in the 

 neighbouring ground of the Alliance Company, it became clear that 

 the horse expands towards the surface to such a degree as to 

 squeeze the vein to (what the miners term) a "feather-edge," 

 and to make it quite disappear at the surface. On piercing the 

 horse, however, at a lower level by a cross cut, it was soon dis- 

 covered, and produced some very rich quartz for a certain extent in 

 length and depth, but gradually became poor afterwards. At 

 240 feet from the surface the western vein showed in this mine 

 the peculiar feature of becoming nearly flat for a distance in strike 

 of about 100 feet, and in dip nearly 40 feet, and then assuming its 

 normal course again (fig. 2). The thickness of the vein at this 

 place is 3-5 feet, and the quartz yielded on an average nearly two 

 ounces of gold per ton. 



Proceeding again southward of the Speculation Company's mine, 

 the reef shows a further change. The eastern vein, hitherto less 

 important than the western one, continues profitably auriferous for a 

 considerable extent in strike, and, ultimately disappearing at the 

 surface, still exists in depth, always*distinguished by its fine smooth 

 eastern wall ; the western vein, on the contrary, soon dies out both 

 in depth and strike. 



Having thus given a short sketch of the reef with regard to its 

 development in the principal mines opened upon it, I will now de- 

 scribe some peculiarities observed in the Alliance Company's mine, 

 in connexion with the interesting feature of the intersection of the 

 reef by different granite-veins. The relative positions of these with 

 reference to the company's engine-shaft are as follows : — 



The first vein traverses the reef diagonally, entering it close 

 south of the shaft, and running northward through it for a distance 



