188 STEVENSON— INTERRELATIONS OF THE FOSSIL FUELS. 



reaching even to i6 per cent, of the dried coal; not a few of these 

 coals have 84 to 87 per cent, of carbon. But not all of the beds yield 

 caking coal, even where its composition is closely similar to that of 

 the others. 



The coals of Lewis county show extremes of variation, for there 

 one finds anthracite with 6.8 of volatile and 93.2 per cent, of fixed 

 carbon in the pure coal, whereas at Mendota the coal is lignite with 

 20 per cent, of water and J^^ per cent, of carbon. At Ladd the coals 

 are bituminous and that from No. 2 is coking. It has 4.1 of water 

 and 84.62 of carbon. It yields 34.2 per cent, of volatile from the 

 pure coal. The other beds mined on this property have only 6 to 8 

 per cent, of water but the volatile is much higher, 43 to 48 per cent., 

 and they are not caking. The ash throughout is high, 18 to 26 per 

 cent, of the dry coal.-*^^ 



Igneous rocks are reported as cutting the coal bearing rocks at 

 a few localities in King and Pierce counties, but for the most part 

 the variation in the coals is regional and apparently is not due to 

 local causes. 



The Alaskan coals show all types from lignite to anthracite. The 

 anthracite coals are in the Bering River region where the carbon 

 content at times reaches 90 per cent. ; but in the same region are 

 bituminous and semi-bituminous coals. The lignitic type, however, 

 prevails in the greater part of the territory. 



At Coal Harbor, Unga of Ball's descriptions, in western Alaska, 

 the analyses give for the coal^ ash and water free: Carbon, 68.76; 

 hydrogen, 5.30; oxygen and nitrogen, 24.89; volatile, 50.29. 



261 E. E. Smith, U. S. Geol. Survey, Bull. 474, 191 1, pp. 42, 43, 

 65, 66, 67. 



51, 64, 



