CAMPBELL.] FIELD WOEK. 19 
bed before it was mined, and the method of mining and of cleaning 
the coal as it was loaded on cars in the mine. After becoming famil- 
ial' with the underground conditions, he visited the tipple and observed 
the manner of handling the coal for market, getting information 
regarding the arrangement of the screens, the grades of coal pro- 
duced, and the method of utilizing slack coal, washing, coking, etc. 
When this was accomplished the inspector supervised the loading of 
a car for testing purposes, selecting run-of-mine, lump, or nut coal, as 
seemed to him most nearly representative of the general output of the 
mine, or in particular cases selecting certain grades for special tests. 
The loading of the car was carefully watched so as to prevent undue 
picking or any irregularity that would tend to make the test sample 
better or worse than the average output. 
In certain cases where a number of cars were in the yards, already 
loaded with what was regarded as representative coal, one of these 
cars was selected at random and shipped to the testing plant. 
In case the car sample consisted of lignite or soft bituminous coal 
such as probably would be affected by weathering in transit, it was 
loaded in a box car, but the great majority of samples were shipped 
in ordinary open coal cars without any protection from the weather. 
Most of this coal was shipped during the months of August, September, 
October, and November, and these months were unusually dry in the 
vicinity of St. Louis. For this reason it seems probable that the coal 
in transit was subjected to little rain or snow, and that the principal 
change caused by weather was a change in amount of moisture due to 
atmospheric conditions which probably affected not only the coal in 
open cars but also that shipped in box cars. 
MINE SAMPLES. 
As an additional check on the quality of the coal, and especially for 
the determination of its moisture content in its native condition, two 
samples were taken in each mine for chemical analysis. These were 
handled as follows: After a general inspection of the mine to deter- 
mine the variations of the coal in thickness and quality, two points 
were selected in opposite or widely separated parts of the mine, and 
after the face of the coal was cleaned of any weathered coal or powder 
smoke, a cut was made across the face of the coal from roof to floor, 
including all of the benches of coal mined and such impurities as were 
not removed in ordinary work. This cut was about 3 inches wide and 
1 inch deep. The coal obtained from it, amounting to 25 or 30 pounds, 
was caught upon an oilcloth blanket spread upon the floor of the mine 
so as to protect the sample from water and from including any shale 
or clay fragments. 
The coal composing the sample was then pulverized and quartered 
down according to the generally accepted rules for preparing samples 
