18 OPERATIONS OF FUEL-TESTING PLANT IN 1905. 
The sample is then mixed by two men who stand opposite each other. Grasping the 
corners of the rectangular blanket, they roll the sample diagonally by raising one corner 
of the blanket at a time. This mixes the sample very thoroughly, and when the larger 
pieces are observed to be evenly distributed throughout the mass the sample is divided 
into four equal quarters. Two opposite quarters are discarded and the remainder mixed 
as before. If the sample is still too bulky to be conveniently handled, it is again mixed 
and quartered. 
The remaining material is spread into a circular mass about 2 inches deep on the blanket, 
and a small trowel is used to fill a sample can with alternate sections of the sample taken 
from the circumferenee to the center of the mass around the entire circle. The can is 
closed and hermetically sealed with electrical insulating tape, and the weight is noted. 
This weight shows accurately what proportion of the original sample is sent to the laboratory, 
The entire process of sampling is carried on as rapidly as possible at the place in the mine 
where the sample is cut. The maximum time for cutting and preparing a large sample 
is about one hour. Although it is known that rapid changes take place in the moisture 
content of some coals, it is reasonable to assume that where the sampling is quickly done 
in the atmosphere to which the native coal is exposed there is probably only a slight gain 
or loss of moisture while the sample is being broken up and quartered. 
In an effort to establish some definite relation between these moisture changes and the 
atmospheric conditions, temperature, humidity, and dew-point determinations are made 
at the beginning and completion of the preparation of the sample. Similar readings are 
taken in the chemical laboratory. When sufficient data have been collected, it is possible 
that this subject will be more thoroughly understood. 
DESIGNATION OF SAMPLES. 
The samples or cars of coal when they are shipped are marked with the name of the State 
and numbered consecutively in the order of shipment. When two or three cars or lots 
constituting different grades of coal, such as lump, nut, etc., are shipped from the same 
mine, each lot is designated by a letter. For example, Illinois No. 1 A may be lump, Illi- 
nois No. 1 B nut, and Illinois No. 1 C slack, etc. These State numbers begin for 1905 
where those in use during the previous work left off. 
SAMPLES RECEIVED AND TESTED. 
The following is a complete list of the car samples received during the period from May 
1, 1905, to January 1, 1906, with details of ownership, location, character of sample, etc.: 
