356 PROCEEDINGS OF SECTION C. 



of the formation. It may also be mentioned that all the 

 water draining from the side of the Mount where the work- 

 ings are situated are rich in sulphate of iron and deposit 

 iron ochre. 



So far as is known at present, the formation is an inverted 

 cone-shaped mass, getting smaller as it descends, and, at the 

 depth of 260 feet below the crown of the hill, in the main 

 tunnel, it break up into thin ore-veins containing ferruginous 

 tin ore, with iron pyrites intermixed. Down to this point the 

 ore is clean and free from pyrites or any other objectionable 

 material. At one time I decided to sink a blind shaft in the 

 main unnel to ascertain the character of these veins and 

 their value at a greater depth, but since the Mount BischofF 

 Company has acquired the North BischofF Valley proj)erty, 

 I have considered it cheapei" and more to the point to explore 

 from that level, which is about 700 feet below the Brown 

 Face working level, and for which work an efficient plant is 

 in course of erection. This course is also more advisable, 

 because the North Valley Lode strikes in the direction of 

 the Mount, and may be found connected, if not with the 

 Brown Face itself, with some of the other workings. 



But, besides the Brown Face deposit, there is another one 

 of not less value, namely, that of the Slaughter-yard Face, 

 which is of great extent. This is worked in different places, 

 and its full length at present known is about 15 chains, and 

 its width several hundred feet. Its strike is about N, 25 E., 

 and it presents a similar character to that of the Brown Face, 

 only that it carries iron pyrites at a shallower depth and is 

 more silicious in places. Its value as an ore-producer is at 

 present unlimited, as it must be fully 200 feet high from the 

 lowest to the uppermost face. 



In addition to the Mount Bischoff workings proper, there 

 are the West Bischoff and the North Valley Lodes. Both 

 have been productive in the early days when only clean ore 

 occurred, but, as depth increased, the admixture of iron and 

 arsenical pyrites somewhat interfered with the success of 

 these companies, as pyritous tin ore requires different treat- 

 ment, and the companies had not the necessary apphances. 

 Still it does not follow that if once pyritous ore is encountered 

 it must continue either in depth or lateral extent, for it has 

 been proved at different times that clean ore came in in 

 patches or shoots below the pyritous ore. This has, for 

 instance, been the case in the West Bischoff Company's 

 workings, where, besides on former occasions, quite recently 



