320 GEOLOGICAL SURVEY OF THE TERRITORIES. 



but by the consumption of more to produce the heat required to expel 

 this water. Hence it is difficult to obtain a strong, concentrated heat, 

 such as is needed for welding iron in the forge-fire, and it is only by 

 particular care and skill that the blacksmiths have generally succeeded 

 in making it answer their purposes. At the machine shops of the Union 

 Pacific Railroad it is not yet admitted' as a substitute for eastern bitu- 

 minous coals, though some of these are brought from Pennsylvania 

 mines, about two thousand miles distant, and the very best of the Rocky 

 Mountain coals are obtained directly on the line of the railroad. As a 

 fuel for locomotives and for domestic purposes, including cooking as 

 well as warming, the coal in general answers very well. It kindles and 

 burns freely, making a bright fire, with a yellow blaze and comparatively 

 little smoke; the odor of this is not so strong or disagreeable as that of 

 the bituminous coals, and somewhat resembles the smell of burning peat. 

 The smoke is not always dark and thick, but is sometimes of a light gray 

 color. The ashes are remarkably light and bulky. The engineers of the 

 locomotives find that some varieties crumble more than others in the fire, 

 and sift through the grate bars; these require closer screens at the top 

 of the smoke-stacks. They endeavor to obtain the coal as freshly mined 

 as possible on account of its sounder condition. Clinkers sometimes 

 form sufficiently to be troublesome when the coals are obtained from 

 those mines that contain seams of slate. There have been a few cases 

 of combustion of refuse heaps of coal, supposed to have occurred spon- 

 taneously. The presence of iron pyrites in coals so easy to crumble and 

 ignite as these cannot fail to suggest this danger, and the importance of 

 guarding all heaps of it from becoming wet. It is not unusual in the 

 llocky Mountain region to meet among the strata of sandstones beds of 

 ashes, which are evidently the ruins of coal-beds, some of which are of 

 large size. The writer has seen many such in the banks of the upper 

 part of the Missouri River. 



The geological position of these coals, together with the considerable 

 proportion of water in their composition, places them in the class of 

 brown coals or lignites, which are for the - most part distinguished by 

 their fibrous structure and close resemblance to the wood from which 

 they are derived. The braunlcoMe of the tertiary formations of Saxony 

 and Brandeuburg, when dug and stacked in the fields, looks more like 

 brown logs of wood than like mineral coal. Other varieties are met with 

 in various conditions of change, and among them some that closely resem- 

 ble the ordinary bituminous coals in their compact texture, brilliant 

 luster, and black color, both of the coal and of its powder, thus differing 

 entirely in appearance from the brown coals or lignites that give a name 

 to the class. This is the general character of the coals of the Rocky 

 Mountains, and their composition shows they are far superior in quality 

 to what the name of the class would indicate. Indeed they appear 

 to be better than the best of the foreign coals of their own variety, and, 

 as they present a wonderful degree of uniformity over extensive terri- 

 tories, it seems they are really entitled to an appropriate name, that 

 should distinguish them, not merely from the common bituminous coals, 

 but from the other lignites also, to which they bear still less resemblance. 



The European lignite deposits are of very limited area, scattered here 

 and there through Prussia, France, Great Britain, &c, and in these 

 small basins the composition of the fuel is very variable. In the Prus- 

 sian provinces above named its value is rated at only one-third that of 

 the genuine coals ; while in the north of Ireland it is considered to be 

 worth two-thirds as much as the bituminous coals. The weight of the 

 ash in the published analyses for the most part exceeds four per cent., 



