GEOLOGICAL SURVEY OF THE TERRITORIES. 369 



into dust, has been profitably used by mixing- it with a certain proportion 

 of moist clay. The same method has been tried in the Lehigh anthracite 

 region of Pennsylvania, where the coal is comparatively of far less value 

 than the lignite of the Eocky Mountains, and large, expensive machinery 

 has been erected for that purpose. As yet these experiments have 

 jn-oved a failure, or, at least, have not given remunerative results. The 

 mixing of clay, or of any other mineral incombustible cement, cannot 

 improve the material, especially not when, as is the case with the liguite, 

 the heating power of the matter in its purity, is not always as strong 

 as required by enginery. It seems very probable, however, that the 

 admixture of bitumen with small coal either pulverized or iu pieces of 

 moderate size, should, by compression of the paste, furnish an excellent 

 combustible material. The bitumen, of course, should be obtained or 

 reduced to the cousisteuce of a kind of glue. I wonder that, with the 

 immense amount of bitumen stored iu the black shale of the Green Eiver 

 group, no trial has as yet been made by some compauj^ foi- the applica- 

 bility of this material. Thick beds of these black shales are exposed 

 all along the railroad from Eock Springs to Bryan and farther. . And 

 some of them are impregnated with so much bitumeu that, as I have 

 said already, the matter is percolating from them through the under- 

 lying sandstone. Though the shales do not consume, they are often 

 used for fuel by the settlers. The coal of Elko Station was for a time 

 burned in locomotives iu the Utah Valley, and this coal is nothing but 

 black shale of the same Green Eiver formation. A few experiments, 

 which would cost comparatively little, would settle this important 

 question, and 1 truly believe that the result would be successful and 

 would confer immense advantage on the people at large interested in the 

 coal-supply of the Eocky Mountains, and still more on the railroad and 

 the instigators of such an enterprise. ]S'ature has done nothing in vain ; 

 this truth cannot be too often acknowledged. This bitumen of the 

 black shale is a complement of the as yet unfinished work of the lignite 

 matter. It depends on the ingenuity of man to render it what it should 

 be, fully appropriate to the wants of that population which is crowd- 

 ing in tiiat, as yet, undeveloped region. 



I do not think, however, that without this improvement of its mat- 

 ter, the lignite, as it is, is inadequate to the present necessity. For the 

 Eocky Mountains, however, the present is nothing in proportion to the 

 promised future. 



In comparing the value of the lignite for heating power, a great number 

 of analyses have been made, and, of course, the results arrived at have 

 not always proved reliable. All the liguite, and the coal, too, contain 

 more or less water, in a degree relative to the progress of decomposition 

 of the woody matter. In proportion as this decomposition advances the 

 amount of water diminishes, and the compactness of the coal increases 

 with its proportion of pure carbon. It is therefore admitted, as a general 

 rule, that the value of a combustible of any kind, or its heating prop- 

 erty, is proportionate to its density. The density for the combustible 

 minerals is sometimes increased by an amount of earthy matter, easily 

 recognizable in the proportion of ashes. In our lignite of the West this 

 exceptionable case is not often remarked, and the lignite-beds of the Eocky 

 Mountains generally give a material of good quality, Aveighing in the 

 average one-lifth less than the best coal of our old Carboniferous meas- 

 ures. Local differences are remarked, of course, but, as I said abo\'e, 

 mos^y resulting from the degree of carbonization of the woody substance 

 which appears to have been increased by the influence of the primitive 

 rocks according to their proximity. It is for this reason that the quality 

 24 G s 



