Marcu 14, 1884.] 
ash, 6.14. Eliminating the ash from these 
analyses, the percentages of the constituents 
of fuel are as follows: fixed carbon, 93.8; and 
volatile matter, 6.2. This result is identical 
with the composition assigned by Newberry to 
a typical anthracite (Johnson’s cyclopaedia, 
me. 1. p.' 993). 
The range of fixed carbon in the analyses of 
these fifteen specimens was from 94 to 80; the 
specimen showing the maximum being obtained 
from near Pottsville, and that showing the 
minimum from near Pine Grove, both from 
the Southern field in Schuylkill county. The 
range in volatile matter in the fifteen analyses 
is from 1.40 to 9.53; the minimum amount 
being in the same Pottsville specimen, and 
the maximum in a specimen from Black Spring 
Gap. The range in ash was from 2.90 in a 
specimen from Tamaqua, to 12.28 in a Pine 
Grove specimen. These results are certainly 
misleading ; for it has been a long-recognized 
fact, that ihe coals obtained in the Southern 
field do not contain the highest percentages of 
fixed carbon. . 
Taylor (Statistics of coal, 2d ed. p. 609) 
gives analyses of a number of Pennsylvania 
anthracites reported from various sources. 
Twelve specimens from the Panther-Creek 
basin, between Mauch Chunk and Tamaqua, 
showed the following : — 
SCIENCE. 
511 
The results which have been reported in the 
Rogers and Taylor tables referred to may be 
taken as those of analyses of mineralogical 
specimens, which were in most cases carefully 
selected, either from the mined coal or from 
special portions of the bed. Im no case, as ! 
believe, are the analyses a guaranty of the 
character of the coal which was being mined 
or shipped as fuel from the individual localities 
at the time that the samples were collected. 
Even the specimens which were collected in 
considerable quantity, and analyzed and tested 
for their evaporative capacity by Johnson for 
the government in 1842 were not, I consider, 
fair averages of the coal which could be com- 
manded in the market from the different mines 
for which his results were reported. 
As indications of the composition of min- 
eralogical specimens, the chemical analyses 
reported by Rogers and Johnson are of little 
scientific value, without a minute description 
of the physical characteristics and geological 
associations of the coal for which they stand. 
This conclusion could be substantiated by a 
number of instances to which I might refer ; 
notably, one where I requested an experienced 
mining-expert to collect duplicate specimens 
from a point in one of the Mammoth bed 
mines, which, when analyzed, showed, much to 
my surprise, the following results : — 
| Averages. | Maximum. | Minimum. 
iene 2. . le 89.21 92.60 86.00 
Volatile matter... . 6.38 §.00 4.54 
il & (2 ee 4.41 7.00 1.28 
Six specimens from the Lehigh region gave — 
| 
Averages. | Maximum. | Minimum. 
- a | 
| | 
Fixed carbon . PP BO.00, (pe “S27 SOM Hea. 85.84 
Volatile matter . . . .| 705° | 9.60 5.36 
ee |) 8.98" | 8.78 1.28 
- 
All of these analyses, particularly those 
given by Taylor, are constantly quoted in 
numerous descriptions of Pennsylvania anthra- 
cite found in technical publications, both at 
home and abroad. The foreign books and 
journals have been reporting the higher re- 
sults; so that the opinion prevails, that the 
hard, dry anthracite mined in the state will 
range from 90 % to 94 % of fixed carbon in 
the market product. Such Le however, not 
the case, as recent analyses’ made by the 
Geological survey show. 
1 Andrew 8. McCreath, analyst. 
latil ixed 
Water eee i Sulphur. 5 Ash. 
1 2.590 3.883 86.233 0.851 
2 2.440 3.998 80.301 0.649 
These two analyses are worthless as indica- 
tions of the fuel-value of the coal, because it 
would be unreasonable to suppose that either 
one or the other specimen, showing such a 
wide range of composition, could be taken as 
a fair average of the coal shipped from this 
mine. Nor are they of scientific value, with- 
out certain facts, connected with the occurrence 
of the coal at this special point, to suggest 
some reason why such wide differences should 
exist. 
If the amount of combustible matter in a 
coal is any criterion of its fuel-value, an exam- 
ination which has recently been made by the 
survey shows how ignorant we are as to the 
actual worth of the different coals which we 
burn, and how readily we may be deceived 
by the special characteristics of a coal which 
we may have noticed, and by which we may 
have judged of its heating-capacity. 
In order to test the value to be attached to 
