burner or in a muffle
furnace. The burning should be kept up until a constant weight is
secured, and it may be assisted by stirring with a platinum rod. The
weight of the residue determines the percentage of ash, and the
percentage of fixed carbon is easily calculated from the loss during the
determination of ash after the volatile matter has been driven off.

Proximate analyses may be made and reported on a moist or dry basis. The
dry basis is that ordinarily accepted, and this is the basis adopted
throughout this book. The method of converting from a moist to a dry
basis is the same as described in the case of an ultimate analysis. A
proximate analysis is easily made, gives information as to the general
characteristics of a fuel and of its _relative_ heating value.

Table 38 gives the proximate analysis and calorific value of a number of
representative coals found in the United States.

TABLE 38

APPROXIMATE COMPOSITION AND CALORIFIC VALUE OF CERTAIN TYPICAL AMERICAN COALS

____________________________________________________________________________
| | | | | |
| | | | | |
No. | State | County | Field, Bed | Mine | Size |
| | | or Vein | | |
| | | | | |
| | | | | |
____|_______|________________|________________|_______________|_____________|
| | | |
| | ANTHRACITES | |
____|_______|_________________________________________________|_____________|
| | | | | |
1 | Pa. | Carbon | Lehigh | Beaver Meadow | |
2 | Pa. | Dauphin | Schuylkill | | Buckwheat |
3 | Pa. | Lackawanna | Wyoming | Belleview | No. 2 Buck. |
4 | Pa. | Lackawanna | Wyoming | Johnson | Culm. |
5 | Pa. | Luzerne | Wyoming | Pittston | No. 2 Buck. |
6 | Pa. | Luzerne | Wyoming | Mammoth | Large |
7 | Pa. | Luzerne | Wy