METALLURGY. . 1381 
» The salt mines at Wieliczka (pl. 26, fig. 1), in Galicia, are justly con- 
sidered one of the wonders of Europe. They extend not only beneath the 
town, but also to a considerable distance on each side; and their treasures 
still appear to be inexhaustible, though they have been worked between 
five and six centuries. 
- The depth of these mines is upwards of 2000 ft.; there are eleven open- 
ings to the surface, and the aggregate length of all the galleries is said to 
be over 250 miles. Many exaggerated stories are told of whole families 
living in the mines and never coming to the surface, but these are entirely 
without foundation. The workmen are divided into three bands, which 
relieve each other alternately, spending eight hours of the twenty-four in 
the mines and the balance above-ground with their families. In 1570 and 
also in 1614 the mine suffered very much from fire, and since then all 
timbering has been discarded, the roof being supported upon pillars of 
rock-salt ; the steps are also cut out of the same material. St. Anthony’s 
Chapel, upon the first floor, about 300 ft. from the surface, is also hewn 
out of the salt rock, as is also the great hall, which contains lustres hanging 
from the roof and all the curiosities, crystals, petrifactions, &c., which have 
been found in the mine. The effect of illumination is said to be truly 
magical in these spacious rooms, and to be enhanced by the varied color of 
the salt, white, pink, grey, and black. 
These mines are supposed to be connected with the salt formation in 
Walachia, having an extent of upwards of 500 miles. 
Vill. METALLURGY. : 
Metallurgy, equally with other branches of art, requires its own peculiar 
implements and tools, the most important of eich we shall notice in the 
sequel. As our ae will not permit us to speak of all the metals, we shall 
select iron, indisputably the most important one, and carry it through the 
different processes to which it is subjected, from the ore to the merchantable 
metal. 
1. GenerRAL PREPARATION OF ORES. 
Metals, united with other mineral substances, in the form of ores, are 
found distributed throughout the crust of the earth, and we have seen 
them extracted therefrom in the foregoing article, by the operations of 
mining. 
Before the final reduction, the ore is more or less separated from foreign 
substances by mechanical means; this it is not, however, possible perfectly 
to accomplish, and the further the 0 egcrig is pushed the greater will be 
the waste of the ore. 
The preparation of the ore commences with the picking or sorting, which 
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