MOUNT BISCHOFP. 353 



what I consider is an older wash, which, when properly 

 prospected, may lead to some valuable discoveries. 



The wash just mentioned was found accidentally when 

 sinking a prospecting shaft at the foot of the hill to fix a 

 point where to start work for tin ore, and also to ascertain 

 whether the stanniferous wash extended further down the 

 slope. This shaft was sunk to a depth of about 35 feet, when 

 the influx of water interfered with further progress. It was 

 never expected to reach that depth, and without timber it 

 became unsafe for the workmen, and had to be abandoned. 

 The sinkstufF consisted of well-rounded boulders of carbonate 

 of iron (siderite), iron and magnetic pyrites (pyrite and 

 pyrrliolite), zincblende (sphaterite), and other minerals of a 

 similar class. At that time I could not connect this forma- 

 tion with anything known in the locality ; but since I have 

 driven the main tunnel through the hill I have come across 

 a serpentine formation containing similar minerals, with the 

 addition of variously-coloured steatite, which I never 

 observed in the wash, but it is not unhkely that this mineral, 

 on account of its extraordinary softness, was ground up, and 

 formed the clayey substance between the boulders. Up to 

 the present moment I cannot find any other formation which 

 may have supplied the material of that deposit. This same 

 deposit extends over a considerable distance along the 

 southern slope of the hill, as proved by two adits, but is not 

 connected with the stanniferous wash in any place. The 

 two drift formations are separated by a layer of micaceous 

 clay, resting again upon pyrites, in places of considerable 

 thickness ; but, as pyritous minerals of any kind are 

 objectionable to mix with tin ore, nothing has been done to 

 explore it. Some thin galena veins have been discovered 

 further west, where solid ground appears to set in, the galena 

 assaying as high as 1 00 ozs. of silver, with a good percentage 

 of lead, per ton. Higher up the hill the true bottom (slate) 

 rises up in an abrupt wall standing from 50 feet to 70 feet in 

 height, with a slight S.S.E. underlay and a strike N. 65° W., 

 which reduced the wash considerably, and the latter ran out 

 eventually towards the Stanhope Company's southern 

 boundary line. In this particular locality topaz-rock with 

 tin ore was first discovered in the washdirt by Professor 

 Ulrich, at present in the Dunedin University, ISi .Z., but then 

 in the Geological Department in Victoria. Later on I sent 

 by a friend of mine a small collection from the mine to the 

 Mining Academies of Clausthal (Hartz Mountains) and 



