GEOLOGY. 315 



COAL TKADE OF GREAT BRITAIN. 



To such an extent has the coal industry of Great Britain developed, 

 that at the present time not less than 37,000,000 of tons are annually 

 raised, the value of -which at the pit's mouth is little less than 10,000, OOO/. 

 at the places of consumption, including expenses of transport and 

 other charges, probably not less than 20,000,000?. The capital employed 

 in the trade exceeds 10,000,0002. About 400 iron furnaces of Great 

 Britain consume annually 10,000,000 tons of coals, and 7,000,000 tons of 

 ironstone, in order to produce 2,500,000 tons of pig-iron, of the value of 

 upwards of 8,000,000?. For the supply of the metropolis alone, 3,600,000 

 tons of coal are required for manufacturing and domestic purposes ; coast- 

 ing vessels conveyed, in 1850, upwards of 9,360,000 tons to various ports 

 in the United Kingdom, and 3,350,000 tons were exported to foreign 

 countries and the British possessions. Add to this that about 120,000 

 persons are constantly employed in extracting the coal from the mines, 

 and that in some of the northern counties there are more persons at work 

 under the ground than upon its surface, and some approximate idea 

 will be formed of the importance and extent of this branch of English in- 

 dustry. The extent of the coal areas in the British Islands is 12,000 

 square miles, annual produce, 37,000,000 tons ; of Belgium, 250 miles, 

 annual produce, 5,000,000 tons ; of France, 2,000 miles, annual produce, 

 4,150,000 tons; of the United States, 113,000 miles, annual produce, 

 6.000,000 tons; of Prussia, 2,200 miles, annual produce, 3,500,000 tons ; of 

 Spain, 4,000 miles, annual produce, 550,000 tons; of British North 

 America, 18,000 miles, annual produce not known. The English ex- 

 ports, which in 1840 amounted to 1,606,000 tons, valued at 576,000?., had 

 increased in 1850 to 3,531,000 tons, of the value of 1,284,000?. In 

 1841 the exports to France were 451,300 tons ; to Holland ,173,378 tons; 

 to Prussia, 116,296 tons ; and to Russia, 77,152 tons. In 1850 they were, 

 to France, 612,545 tons ; to Holland, 159,953 tons ; to Prussia, 186,528 

 tons; and to Russia, 235,198 tons. 



LARGE SPECIMENS OF COAL. 



Among the mineralogical curiosities exhibited at the New York Crystal 

 Palace were four columns of anthracite coal forwarded from. "Wilkesbarre, 

 Penn., and taken from four overlying seams in the Wyoming Valley. 

 These columns were of the following dimensions : 



1. A single block, 3 feet in height by 2 feet square, from the upper or 

 three-foot stratum, and designed, as are all the different columns, to show 

 the thickness of that vein. 2. A column, in two sections, measuring six 

 feet and a half high, the thickness of the seam from which it is taken. 

 3. A column, in three sections, nine and a half feet in height, the thickness 

 of that seam. 4. A column, in five benches or sections, measuring thirty 



