METALLURGY. SO 



modern Westphalian and Swedish stoves, as built at 

 Tagilsk, the Katov stove with suspended pipes, and the 

 \Vhitwell or Cowper stoves yield much higher tempera- 

 tures. As a rule the older blowing engines are vertical, 

 and have one cylinder, while those more recently put up 

 have two. Oscillating engines are rarely built; one at 

 Nijni Tagilsk is of this type. The pressure is low, 

 being between 2'95 and 3 94 inches. Only a few modern 

 blowing engines like that at Nijni Saldinsk furnish 

 blast at a pressure of 4'91 to 6'88 inches.* They are, as 

 a rule, driven by water power, and steam-engines have been 

 erected only at some furnaces to act as a reserve in case 

 of scarcity of water. 



' The furnaces are so built that ore and fuel are brought 

 to the top by means of a bridge ; but in plants recently 

 put up, as in Southern Russia, and at !Nijni Saldinsk, 

 power or pneumatic hoists are used. Generally ore and 

 fuel is charged by hand, and only occasionally by barrows. 

 The charge is so chosen as to produce a slag approaching 

 a bisilicate. In the Ural mountains grey or mottled pig, 

 of exceptional purity, and suitable for the manufacture of 

 steel, is obtained from pure magnetites, while foundry pig 

 is made with the aid of fluxes. At Jurjazan, spiegeleisen, 

 holding from 10 to 12 per cent, of maganese, is produced 

 from brown ores from YisokajaGora, mixed with maganese 

 ores. Ferromaganese is only made at Tagilsk. In the 

 north of Russia, as at Kamensk-Kasla, excellent foundry 

 pig is made from pure brown iron ores, and at Peskov a 

 similar grade is produced from specular ores. In Central 

 Russia, Olonec, and Poland, castings are made direct from 

 the furnace. In Finland, at Abo, and Njuland, an excel- 

 lent grade of refinery pig is produced from iron glance 

 brought by sea from Sweden, while the works of Central 

 Russia yield only metal containing phosphorus. 



' The following table gives the dimensions, number of 

 tuyeres, temperature, and pressure of blast, charges smelted, 

 iron produced, fuel consumed, and quality of iron : 



An inch of mercury equals about one half-pound pressvue. 



