1002 



The Tin district of New South Wales from the commencement of the workings for 



tin unto the present time : 



Ore Smelted Ingots 



Cwts. Cwts. 



1872 20,682 .... 1,838 



1873 

 1874 



78,300 . 



19,055 for six months 



20,595 



45,661 for six months. 



Tasmania. Tin ore has also been recently discovered at Mount Bischoff. in the 

 north-western part of Tasmania. The ore is not only found as an alluvial deposit, 

 but occurs in a porphyritic rock, resembling some of the Cornish elvans, and is in 

 many places intimately associated with a gossany oxide of iron. It will be seen from 

 the general statement of imports that a small quantity was sent from this colony. 

 Large masses of tin have been found in the alluvial deposits, evidently derived from 

 lodes ; and we understand some lodes have been discovered. 



Tin Dressing. Most of the tin ores in Cornwall have to be roasted, or calcined, be- 

 fore they are fit for the smelting-house, although in some mines the admixture with 



1984 



other minerals is so trifling that this operation is considered unnecessary. The fur 

 nacK(jtgs. 1983, 1984) in which the roasting is carried on, is about 10 feet long, 5 feet 

 6 inches wide in the middle, and 3 feet wide near the mouth. The fireplace, it will be 

 observed, is situated at the back, the flames playing through the oven and ascending thu 

 chimney, which is above the furnace-door. The man is represented in fig. 1983, as stir- 

 ring the ore with along iron rake. The ore, before it is submitted to the action of the 

 fire, is thoroughly dried in a circular pit, placed immediately above the oven, into which 



