HISTORY AND USE. The value of coal does not seem to have been known to the ancients, nor is it well known at what time it began to be used for fuel. Some say that it was used by the ancient Britons; at all events, it was an article of household consumption to some extent during the Anglo-Saxon period as early as A.D. 852. There seems to be reason for thinking that Eng land was the first European country in which coal was used in any considerable quantities. In America the deposits near Richmond, Va., were discovered.in 1701, and mining was begun in 1750, while anthracite was first produced in 1793. Extended coal-mining in the United States did not really begin, however, until about 1820. Since that time up to the present, the increase has been about 3500 per cent. In 1822 the amount of coal mined in Virginia was about 48, 000 long tons. Now the production for the United States is about 270,000,000 short tons, or greater than that of any other country of the world.
Coal is used largely for domestic purposes, either as fuel or, in the form of gas, for illumina tion. Its use for the latter purpose is, however,
not so widespread as formerly, water-gas having superseded it to a considerable extent. In the pro duction of steam for motive power it also finds important applications. It is furthermore widely employed in the metallurgical industry in the form of either coal or coke, and in this connec tion may serve both as a fuel and as a reducing agent. Coke (q.v.) is made only from bitumi nous coal. Lignite seldom has much value as a fuel, owing to the large percentage of moisture that it contains. Because of this moisture it tends to crack in drying, and must therefore be used soon after mining, and in localities where it does not require long transportation from mine to market. This is true, for instance, of some of the lignite deposits in Colorado which are near the Denver market, and therefore possess commercial value. Lignite has sometimes been successfully used in the manufacture of producer gas, and indeed even peat has been found adapt able for this purpose.