How do they dig salt mines?
Most underground mines are spooky tunnels, grim and gloomy. But underground salt mines are different. The walls of a coal mine are blacker than midnight. But an underground salt mine has pale walls that may glisten like frost. Its tunnels may be as wide as streets and as high as tall churches. One of the most famous salt mines is in Poland. Its elevator shafts go down, down to 1,000 feet below the surface. On the way, they go through 65 levels of tunnels, called galleries. The different levels have railroads to carry the miners to work. They also carry out carloads and more carloads of rock salt. This lumpy stuff is called “halite.” It is the ore from which we get ordinary salt. Halite is a pale rock, glassy brittle and sometimes glassy clear. As a rule, it is tinged with dingy greys, yellows or rusty browns. The people of Poland have been digging their big mine for more than 100 years. In places, the miners have carved statues from the halite, and tourists come from afar to see them a
