88 FORESTRY IN EASTERN RUSSIA. 



in Poland a basket of 46 cubic feet* Wood is charged in 

 some places in Central Russia and Finland, in a dried or 

 charred state, the pieces being split and cut to 13-inch 

 lengths. 



' The furnaces are, as a rule, old, with massive masonry 

 of brick or stone, the shaft and boshes being circular, while 

 the hearth is rectangular. The lower part of the lining is 

 usually built of stone, which material is often used also for 

 boshes and shaft. Brick is not common. They generally 

 have an open top, the gases either being allowed to escape 

 from the tunnel head or being taken off by a flue. The 

 front, too, is open in most cases, only a few furnaces in 

 Central Russia, in the Ural mountains, and in Poland, 

 having a closed front. The number of tuyeres is two or 

 three, and sometimes only one ; their diameter, however, 

 is large. The blast is, in most instances, cold, and the 

 pressure low. The height and diameter of the furnaces 

 vary. In Finland and Olonec they are only from 29'5 to 

 34 feet high ; in the Ural mountains the height is gene- 

 rally 49 feet and upwards, while the average in Central 

 Russia is 39 feet. Modern furnaces have from 3 to 12 

 tuyeres, the masonry of the hearth is water-jacketed, and 

 their section is either round or ellipitical, according to the 

 Raschett model, and the shafts are built free. Hearth and 

 shaft are made of brick, but often, as at the Peskov works, 

 the Scotch system has been adopted, while in other cases 

 the furnaces, like the Nijni Tagilsk No. 3, and the 

 Nijai Saldinsk, the Biittgenbach system has been 

 chosen. Modern furnaces all have hot blast stoves heated 

 by gas, the furnace top being closed by the Langen, Parry, 

 or Frohlich charging apparatus. In many cases the waste 

 gases are also used for making steam, as at Kuschava 

 Tagilsk, and occasionally also for roasting ore. The con- 

 struction of the hot blast stoves varies. In the Ural 

 mountains the Wasseralfingen pipes are put up above 

 the level of the tunnel head, in Central Russia the Calder 

 stove yields blast heated to 150 degrees C. (302° F,), whilst 



" Equal to 29 iushels. 



