16 PRELIMINARY REPORT ON COAL-TESTING PLANT, [bull. 261. 
FIELD WORK. 
The field work was placed in charge of Mr. M. R. Campbell, one of 
the committee appointed by the Director of the Survey for the prose- 
cution of these tests, who was assisted throughout the field season by 
J. Shober Burrows and John W. Groves, and for a short time by 
Frank W. De Wolf. All of the coal shipped to the plant for testing, 
with the exception of a few carloads, was collected under the supervi- 
sion of one of these Survey officials. This was done to avoid any pos- 
sibility of the criticism that selected coals had been subjected to these 
tests. 
SAMPLING. 
When the coal was shipped the Survey representative sampled it at 
two working faces of the mine, and the samples so obtained were 
shipped to the chemical laboratory for analysis. When the car was 
unloaded at the testing plant, what is known as a "laboratoiy car 
sample," consisting of about 200 pounds of coal, was taken from every 
car and sent to the laboratory, where the coal was pulverized, quar- 
tered down, and analyzed. Again, as the coal was distributed to 
different portions of the plant for testing, other samples were taken 
in a regular and uniform manner and sent to the laboratory for analy- 
sis. Such a series of coal analyses has never before been made in this 
country. 
REPORTS. 
The preliminary reports of the operations of the different 
portions of the plant have been prepared by the experts in charge. 
A more detailed report, which will be fully illustrated by photo- 
graphs, graphic charts, etc., and which will give the methods em- 
ployed and results obtained in much greater detail, is in preparation, 
and will be published at the earliest possible date, 
RESULTS. 
It will be necessary to test a larger number and greater variety of 
coals and lignites, and to repeat with greater care some of the tests 
already made, before a full discussion of the results of these investiga- 
tions can be properly entered upon or their value fully appreciated. 
But the results already obtained from the preliminary investigations 
made during the last six months are sufficient to indicate their far- 
reaching importance in the solution of the fuel and power problems 
upon which the varied industries of the country depend. 
Among the results already clearly indicated by these prelim inary 
tests the following may be stated as worthy of special consideration: 
(1) The tests in the steam-boiler plant of 65 carload samples of coal 
from 17 States indicate the high steam-producing capacity of American 
