116 COAL IN ENGLAND. 



peculiar changes alluded to. The agency of pressure and heat in 

 these changes from organized vegetable bodies to anthracite coal, 

 have therefore been apparent in producing the chemical changes which 

 have marked their transformation. 



Some of these coal beds are worked at a depth of 1,000 feet; but 

 in this country, there is no occasion to work anthracite to a great 

 depth, as it is elevated and the beds are numerous and extensive. It 

 has been said of the British coal measures, limited as they are com- 

 pared with those of this country, that they are the most valuable of 

 all the mineral substances from which Britain derives her prosperity, 

 and indeed may be regarded as the main support of the whole system 

 of British production." If this be true in regard to G. Britain, of how 

 much importance are our vast coal productions to the present and fu- 

 ture prospects of our country. The annual consumption of coal in 

 the kingdom is estimated at 28,575,000 tons, giving employment to 

 200,000 persons. The exports are 7,190,433 tons. There is shipped 

 to London alone 2,638,256 tons by 7,500 vessels. Coal was first dis- 

 covered in Eng. at Newcastle in 1300, and was first taken to London 

 in 1381 ; but Edward 1st, supposing it corrupted the air when burned, 

 forbade its use by proclamation. It has been calculated that there 

 is a sufficiency in G. Britain for 3000 years ; but this does not appear 

 probable from the fact that they are already worked to an immense 

 depth to supply the present demand ; while the vast regions of coal 

 near the surface and yet unwrought in the U. S. render our resources 

 in this respect, truly inexhaustible. 



There were raised of anthracite in the U. S. in 1840, 850,926 tons, 

 of which 859,676 were raised in Penn., 1,000 in R. I., 200 in Va., and 

 50 in N. C. ; men employed 3,013 ; capital invested $4,450,112. Of 

 bituminous coal there were raised 1,533,015 bushels, of which 622,345 

 were raised in Va., 620,654 in Penn., in Md. 222,000, Conn. 38,000,, 

 and in N. Hamp. 29,920. 



The varieties of coal are numerous. These may be accounted for 

 by the natural changes which have taken place in the history of the 

 earth. The bituminous coals burn with a bright flame and most freely, 

 They are supposed to possess most hydrogen, while the anthracite is 

 composed mostly of carbon. This does not appear from their combustion 

 to be always the case. The difference may be attributed to the differ- 

 ent states of combination in which these elements are found. They 

 are less coherent in the hituminous coals; and the soot given off may 

 be equivalent to the carbon of the carburetted hydrogen burned in the 

 anthracite. The bituminous coals are divided into the black and the 

 brown cvals. Of the latter is the bituminous wood, with a ligneous or 

 woody structure and without lustre. Earthy coal is less coherent and 

 the particles are loose and friable. The moor coal has no ligneous 

 structure and is without lustre j it splits readily on removal. The 



