66 



the passageway between two others which have been ahnost burnt out, 

 the latter plan adding very materially to the capacity of the roast yard. 

 After this operation the ore is invariably so thoroughly roasted that it is 

 necessary to add from lo to 25% of raw fine ore during the smelting to 

 prevent the matte from being too rich. Each pile usually contains 

 about 600 tons of ore, and requires 30 cords of wood to roast it. The 

 roast yard at Copper Cliff is nearly half a mile long by 100 feet wide, 

 while each pile occupies a space of 40 x 80 feet, room being left to get 

 round them, and for drains. The present capacity is about 60,000 tons, 

 which, with a little extra work, could be increased to 90,000 tons. 

 Working full power each roast bed can be used four times a year, 

 counting the time in making, roasting and clearing the beds. The yearly 

 capacity would therefore be 240,000 tons, and by increasing the space, 

 360,000 tons. The unroasted ore contains from 35 to 40% sulphur, 

 and assays of a large number of samples of the roast heaps have varied 

 from 2^ to 8% of sulphur. One analysis taken at random which may be 

 taken as a fair sample of all the rest, gave 5.40% copper, 2.43% nickel, 

 7.92% sulphur and 25% iron, lime, magnesia, etc., and the residue 

 chiefly hornblende. Up to October ist, 1890, 56,534 tons had been 

 taken to the roast yard. 



SMELTING OF THE ORE. 



There are two smelting furnaces at Copper Cliff, and the building 

 which contains these is 65 feet long by 40 feet wide. Thirty-five feet 

 of this length is on a level with the ground, while the rest of the floor is 

 8^2 feet higher, and it is on this upper flat that the ore and fuel bins 

 are situated. The daily capacity of each of these furnaces is 125 tons, 

 although one of the furnaces has reduced 187 tons of ore in one day, 

 and the furnace manager says that 135 tons could be reduced without 

 much forcing. The furnace itself is a steel plate water jacket of the 

 Herreshof patent, made in Sherbrooke, P. Q., by the Jenckes Manu- 

 facturing Co'y. It is nearly oval in form, the longer diameter at the 

 tuyeres being 6 ft. 6 in., while the shorter one is 3 ft. 3 in. There are 

 II 2)4 in. tuyeres through which the blast enters from a Baker's rotary 

 blower under a pressure of about 9 oz. per square inch. It is 9 feet 

 high from these tuyeres to the charging door, and is an unbroken water 

 jacket from the cast iron bottom up. It is made of rolled steel with 



