352 PROCEEDINGS OF SECTION C. , 



show the producing power of this Company. At the 30th 

 June last the ore produced amounted to nearly 37,088 tons, 

 to the value of £2,300,000, out of which dividends were 

 declared to the amount of £1,138,500, besides the dividend 

 tax of over £46,000, The money expended before the first 

 dividend could be declared amounted to the nice round sum 

 of £100,000. 



Geology of Mount Bischoff. 



The geological formation of Mount Bischoff consists prin- 

 cipally of old slate and sandstone — as far as yet proved, non- 

 fossiliferous — and is intersected by numerous dykes of" eurite " 

 or " quartz-porphyry " and " topaz-porphyry," which latter 

 rock we may consider almost wholly accountable for the ore 

 formation. The intrusion of these dykes has produced some 

 alteration in the above sedimentary rocks by converting them 

 into a rock resembling hard chert. The dykes strike from 

 the Mount (2650 feet above sea-level) in all directions, 

 except northward, which is, so far, not proved as yet ; but I 

 have no doubt they will also be discovered in that direction 

 should the ground be cleared of the surface soil. One of the 

 principal ones is that connected with the Brown Face, which 

 forms a crescent of considerable sweep and length ; others 

 crop up only here and there, and show, therefore, interrupted 

 lines. All these dykes within a certain zone are more or 

 less stanniferous, and must have played an important part in 

 the drift formation of the district. On this account we may 

 class the tin ore occurring at the Mount in two distinct 

 parts — the stanniferous drift and the lode tinstone formation. 



The former was principally worked in the early days of 

 the Bischoft mine ; in fact, for more than seven years nothing 

 but washdirt was worked, and only when by calculation it 

 was found that the supply could not last above a certain time 

 attention was directed to the latter. One pecuhar feature in 

 the drift formation is that it started at the foot of the 

 southern slope, extending both east and west, in a very thin 

 layer, and resting on the bottom, showing an angle of from 

 40° to 45° rise, and this continued so for at least a couple of 

 hundred feet ; and it only increased in thickness when the 

 bottom began to take a flatter inclination. Its greatest thick- 

 ness on the southern slope was over 70 feet, good tin-bearing 

 dirt from top to bottom. The remarkable part of this 

 formation is that it does not rest on a true bottom, but on 



