33^ TRANS. ST. LOUIS ACAD. SCIENCE. 



but it is reported by citizens to thicken locally to 2, 3, 4^ and 

 even 8 feet. Certainly it thickens materially eastward, as indi- 

 cated by the Macon boring record of 31.^ inches, and the observed 

 thickness of 33 to 25 inches on Salt river — where, again, extrava- 

 gant claims are made concerning its thickness and quality. It is 

 a reasonable inference that the thickness continues to increase 

 eastward until the bed is cut off" by erosion probably near the 

 county line, as the Bevier coal is cut off' on the "grand divide" ; 

 and there is presumptively a corresponding attenuation westward. 

 Its area is approximately represented in the accompanying map. 

 Fig. I. The Carbon coal was formerly worked largely at the 

 now defunct town of Carbon and elsewhere ; but since the great 

 development of the Bevier mines took place its extraction has 

 been confined to a few drifts and open workings operated in a 

 small way to meet local demands. It is doubtful whether this 

 field can be successfully brought into competition with the Bevier 

 and other coal fields of Missouri, at least for the present, and for 

 the portion lying westward of the "grand divide," but judicious 

 prospecting and exploitation along and east of Salt river is ad- 

 visable ; and eventually the Carbon coal will form a resource of 

 great value. 



