THE LOWER COAL MEASURES. 151 
it. It should be clean and bright, and it should also have strength 
enough to bear all necessary handling without excessive breakage. 
According to such a standard, the coal of the Sharon seam, and 
especially in the Massillon district, would be entitled to the first place, 
but it would be followed close by several other coals. There are many 
large coal fields, and some entire seams that make no attempt to enter 
this market. 
2. High quality in a coal will tell upon its efficiency in the pro- 
duction of steam as promptly and certainly as in any other use, but 
poorer quality is less objectionable and offensive here than elsewhere. 
Chemical and physical properties that would wholly exclude a coal from 
certain of the higher uses may not interfere with the wide and accept- 
able use of the same coal in the production of steam. A coal that 
mines small, or that is too tender to bear handling, is ruled out of the 
market for domestic use, but such points count little or nothing against 
it as a steam coal at the present time. Both locomotive and stationary 
engines have been lately adjusted so as to successfully use the smaller 
grades of coal, nut, pea, and even slack. The yard engines of many 
railroads, and the freight engines of some, do all their work on pea coal 
and slack. This great saving of fuel, often derived from the best part 
of the seam and entirely lost hitherto, is a matter of great importance 
to the coal fields and the State as well. 
The “strength” of the coal, or its absolute heating power, seems a 
matter of more consequence in a steam coal than the nicer points of 
composition. . 
All the coals of the State, from the purest and best, to the seams of 
lowest quality, do duty «s steam coals, but there are some seams that 
are practically limited to this service. The Upper Freeport coal is an 
example of this class. It is one of the most important seams of the 
Coal Measures, but every year fixes its character more definitely and 
exclusively as a steam coal. Its high percentage of fixed carbon 
ensures its efficiency, and its tenderness under handling works less 
against it here than in most other applications. 
Open-burning and cementing coals are used promiscuously by the 
same railroad often, but probably not without some disadvantage. Each 
coal has its own behaviour on the grate-bars, and each gives better 
results when treated in one way than in other ways. The neglect to 
study and recognize these “ personal equations” of the different seams, 
