Prof. C. H. Hitchcock— The Coal Area of the U. States. 101 



prising more than 100,000 square miles. It is also readied by- 

 several navigable rivers. It extends from Iowa to Texas. It is 

 separated from the Texas field only by Cretaceous beds, which 

 probably overlie coal beds continuous from one basin to the other. 



In Iowa, ^ Professor White's late map shows an area of about 

 25,000 square miles of Coal Measures. He has divided the group 

 into three divisions, each about 200 feet. The two lower ones con- 

 tain the workable coal, which amounts to eight feet in the second, 

 and only twenty inches in the upper division. As the lower 

 divisions everywhere pass under the higher, the whole area may be 

 regarded as productive- 

 Nebraska contains 3,600 square miles of the Upper Coal Measures, 

 according to map in Final Eeport upon the Geology of Nebraska, by 

 F. V. Hayden. 



In Missouri (private communication) Professor GT. C Swallow 

 estimates the coal area at 27,000 square miles, and in Kansas at 

 17,000 square miles. The Measures are 2,000 feet thick, carrying 

 twenty coal beds, from a few inches to six feet thick. 



In Arkansas, Dr. D. D. Owen" describes two coal beds, the 

 thickest five feet thick, and very valuable. The area is stated to be 

 12,000 square miles. This coal, however, underlies the conglome- 

 rate, and does not belong to the true Coal Measures. 



Scarcely anything is known of the coal in Indian territory. 

 From the map, the area must be as great as that of Arkansas. I am 

 assured by the officers of the Missouri, Kansas, and Texas Eailway, 

 that they find good beds of coal all through the territory near their 

 line of travel. 



7. The Texas Basin. — This is barely separable from the preceding. 

 Dr. B. F. Shumard^ estimated the coal area at 5000 square miles. A. 

 B. Eoessler^ estimates the same at 6000 square miles. Beds of good 

 coal are reported at Fort Bilknop, four feet in thickness. 



8. Mr. G. K. Gilbert,'^ of the expedition under the immediate 

 direction of Lieut. George M. Wheeler, reports coal near Camp 

 Apache, in Arizona. Carboniferous strata are known in many places 

 in the mountainous territories, and valuable discoveries of coal may 

 be looked for among them at no distant day. 



The total coal area as thus described amounts to 230,659 square 

 miles. No notice is taken of any coals which do not belong to the 

 Carboniferous system. There are many others of commercial im- 

 portance, as the Triassic of Virginia, the Cretaceous of the Terri- 

 tories west of the Missouri Eiver, an immense amount in California, 

 Alaska, etc. 



These facts will afford data for those who are interested in esti- 

 mating the amount of coal in different coimtries by the number of 

 cubic miles or tons. The statements are too brief to permit any 

 notice of the best or of the inferior coal. 



* Geology of Iowa, by C. A. White. 



^ Second Eeport, Geology of Arkansas, by D. D. Owen. 



8 Texas Almanac for 1861. * Ditto, for 1872. * Official Report. 



