BERING RIVER COAL. 75 
It will be no.ticed that in most of these samples there was a large amount of total mois- 
ture, the greater part of which was driven off by air drying. « Under most circumstances 
this would be regarded as excessive and not characteristic of fair samples. But in view of 
the large amount of underground water which the rocks of this region contain and the 
heavy rainfall, it seems probable that the total moisture of these analyses will represent 
approximately the proportion which the coal will contain in uncovered ears when it reaches 
tide water. 
The first seven analyses in this table are characteristic of the anthracite coal. They 
show it to be of excellent quality, some of the samples, especially of the thicker beds, being 
remarkably low in ash. 
Samples No. 8 and No. 9, which are from the west slope of Carbon Mountain, near the 
crest and near the southern edge of the coal belt, are higher in volatile matter than the rest 
of the coal in this part of the field, and should probably rank as semianthracite rather than 
as true anthracite. They are, nevertheless, of excellent quality, being purer, regarding both 
ash and sulphur, than some of the anthracite. They resemble the anthracite in appearance 
and will probably be classed as such by the trade. 
The remaining analyses indicate a coal which is on the border line between semibitumi- 
nous and bituminous, according to the definitions of Frazer in the reports of the Second 
Pennsylvania Survey, or between semianthracite and semibituminous, according to the 
more generally accepted trade classification. The coal is very close in composition to the 
Pocahontas (West Virginia) coal and to some of the other similar coals of the Applachians 
and of Arkansas. Comparisons with other coals are made in the tables of analyses and dis- 
cussions in another paper in this bulletin. & 
COKING TESTS. 
The coal from the 33-foot bed on Trout Creek (see p. 71) was tested in the following man- 
ner: A hot wood fire was built in a pit dug for the purpose and lump coal gradually added 
until about 600 pounds of coal was burning. Then about a ton of coal was added. The 
sides of the pile were banked with stones and dirt, the top and ends being left open for draft. 
After several hours the ends were covered, and only a small opening at the top was left 
uncovered to let the smoke escape. Four days later, when the smoke ceased to come off, 
the pile was opened and the fire extinguished. The resulting coke was firm, strong, and 
porous, and had a good ring and luster. The test showed conclusively that an excellent 
coke can be made from this coal. 
Coal from many of the other seams was tested more crudely, and it was found that prac- 
tically all of the coal here classed as semibituminous possesses such coking qualities that 
there is little or no doubt that by proper treatment a good coke can be made from almost 
any of it. 
CONDITIONS FOR MINING. 
The problems which will affect the cost of mining in this region include the friable char- 
acter of the coal, steep dips, complicated structure, variability in thickness, possible lack of 
persistence of the seams, the occurrence of explosive gases, and large amounts of under- 
ground water. 
The friability of the coal, if it persists beyond the zone of surface weathering, will very 
seriously affect the market value of the anthracite. If the anthracite yields a large propor- 
tion of slack, and especially if it crushes during transportation, it will be at a decided dis- 
advantage in the market. No openings on the anthracite have as yet been driven beyond 
the zone of surface disintegration, so it is impossible to tell whether or not the coal below the 
a Each sample of coal, after a rapid preliminary crushing to about one-fourth inch size and reduction 
in bulk by quartering where desirable, was weighed and then exposed to the air for about twenty-four 
hours, or until the loss of weight on further exposure became slight. The loss of weight thus deter- 
mined constitutes the "loss on air drying," and is represented in the table of analyses by the difference 
between "total moisture" and "moisture in air-dried sample." 
& Markets for Alaska coal, pp. 18-29. 
