98 



SURVEY OF COLORADO AND NEW MEXICO. 



Asll 



Salphur 



6.17 



2.88 



Color of ash, liglit gray. Spec:fic gravity, 1.37. Weight per cubic 

 yard, 2,212 pounds. 



My assistant, Persifor Frazer, jr., in the United States geological sur- 

 vey of Colorado and Kew Mexico during the past season, has made the 

 following analyses of coals along the line of the Union Pacific railroad. 

 They were made with great care and I have the most perfect confidence 

 in their accuracy : 



Coal from mine at Point of Rocks : 



Per cent. 



Carbon 64.70 



Ash 4.40 



Sulpliur •- 0.42 



Water and volatile substances 30. 48 



Total 100. 00 



Coal from Rock Creek : 



Per cent. 



Carbon 61.34 



Sulphur 2.00 



Ash 1.50 



Volatile substances and -water 35. 16 



Total 100.00 



Coal from Black Buttes : 



Per cent. 



Carbon 71.64 



Sulphur 2.00 



Ash 2.50 



Volatile substances and water 23. 86 



Total 100.00 



Coal from the Evanston mine was tested for its carbon alone and found to contain 

 carbon, 72.16 per cent. All these coals resemble in their physical properties those 

 met with along the route of the Colorado and New Mexico survey. 



I take the liberty of quoting in this connection the following analyses 

 of coals from the admirable report* of my friend Doctor J. H. LeConte. 

 I found this report, as well as that of Doctor Kewberry, of great service 

 to me in my explorations during the past season : 



*N'otes on the ceolojry of the survey for the extension of the Union Pacific Railway, eastern division, 

 from tlie Smoky Hill River, Kansas, to the Rio Grande, by Jolm L. LeConte, page 58. 



tThe analyses of tlie Marshall coal and that of Coal Creek were made by Doctor Torrey, and are 

 copied from Doctor Hayden's paper in Silliman's Journal for March, 1868 



