The selection of fuels will depend on the type of heating plant in use, whether by stoves or by furnaces. If by stoves, whether it is possible to use soft coal as a fuel. The automatically fed stove, of the base-burner type, are usually designed for the use of hard coal and in such stoves the use of soft coal would not be possible. Other stoves and furnaces are usually capable of burning soft coal with varying degrees of satisfaction, depending on the design and surrounding conditions. The following prices, from the local market, show the usual ratings of various fuels in common use. These prices vary with the locality and somewhat with the season. It is usually possible to purchase coal at some reduction in price during the summer months when the demand for coal is light. Hard coal--stove size $10.25 per ton Hard coal--nut size 10.50 per ton Semi-bituminous--run-of-the-mine 9.00 per ton Pennsylvania bituminous--run-of-the-mine 7.50 per ton Soft coal--Ohio--run-of-the-mine 7.50 per ton Soft coal--Illinois--bituminous--run-of-the-mine 7.50 per ton Soft coal--Iowa--bituminous--run-of-the-mine 7.50 per ton Briquettes-mixture semi-bituminous coal dust 9.00 per ton Wood (oak), sawed, stove length and split 8.50 per cord The price of coal is determined in many localities by the distance from the sources of supply and the means of transportation. The fact that coals from all of the principal mining areas from Pennsylvania, west to Iowa, are sold at points in the Northwest for the same price, is due in greatest measure to transportation rates on the Great Lakes. The prices of Eastern coals at Duluth are such that in competition with Western coals they are sold at the same price as is shown by the table. It is usually impossible for the average householder, or even the dealer, to determine definitely the exact locality from which his fuel is mined. Even when such information is obtainable, the quality is still in doubt, unless analysis is obtainable by sample. The data given in the following tables is such as will furnish a fair knowledge of the relative heating values of coals from the principal mining areas of the United States. The data was obtained from a considerable number of authorities but chiefly from the reports of the United States Geological Survey. The different items are not intended to be exact, they merely represent reliable average conditions. The varying conditions of available heat and percentage of moisture given in the following table are such as to be of little use to those unaccustomed to problems of this kind, unless a systematic method of comparison is made of the different fuels. APPROXIMATE COMPOSITION AND CALORIFIC VALUE OF TYPICAL AMERICAN COALS