.MINERAL COAL. 



89 



2500 square miles of which are in Nova Scotia At Cape 

 Breton is still another field of coal. 



The coal of Rhode Island and eastern Pennsylvania is 

 anthracite. Going west in Pennsylvania, the anthracite 

 becomes more and more bituminous ; and at Pittsburg, at its 

 western extremity, as also throughout the western states, it 

 is wholly of the bituminous kind. The Rhode Island variety 

 is so hard and compact and free from all volatile ingredients, 

 that for many years it had been deemed unfit for use. The 

 anthracite of eastern Pennsylvania affords 3 to 6 per cent, 

 of aqueous vapor, and 1 to 4 per cent, of volatile combustible 

 matter. In the Bradford coal field, lying near the eastern 

 limits of the bituminous coal deposits, Prof. Johnson obtained 

 1 to 8 per cent, of moisture, 9 to 15 per cent, of inconden- 

 sable gas, 5 to 17 of earthy matter, and 62 to 75 of carbon. 

 In the bituminous coal of the Portage railroad, Cambria 

 county, Penn., he obtained 18*2 per cent, of volatile com- 

 bustible matter ; in that of Caseyville, Ky., and Cannelton, 

 Indiana, 30 to 34 per cent. ; and in a coal from Osage river, 

 Missouri, 41*35 per cent. The general fact that the pro- 

 portion of bitumen increases as we go westward, is here well 

 exhibited. 



Some of these results, derived from an extensive series of 

 experiments, are thus averaged by Prof. Johnson : 





Moisture. 



Vol. Combustible 



Ashes and 



Fixed 





Matter. 



Clinker. 



Carbon 



Pennsylvania anthra- ) 

 cites, ) 



Maryland free burn- > 

 ing bituminous coal $ 



1-34 



3-84 



737 



87-45 



1-25 



15-80 



994 



7301 



Pennsylvania free \ 











burning bituminous > 



0-82 



1701 



13-35 



68-82 



coal, ) 











Virginia bituminous, 



1-64 



3663 



10-74 



50-99 



Cannelton, Indiana, ) 

 bituminous, \ 



2-20 



33-99 



497 



58-44 



It has also been shown that this fact is connected with the 

 geological condition of the country, the anthracite occurring 

 in the east where the rocks are variously uplifted and thrown 

 out of position by subterranean forces, evincing also other 



What is the relative geographical position of the anthracite and bitu- 

 minous coal in the United States? What has probably made <>he dif 

 ference in these two kinds of coal? 



8* 



