900 
Since the Philippine coals used in this study were of the upper or 
outcropping beds, in which naturally the percentage of ash and especially 
of moisture, due to climatic conditions, is higher than the average, it 1s 
only fair in comparing the results with those of other lands, to do so on 
the basis of the yield of gas per unit of combustible matter. It will 
be seen from Tables X, XI and NII that the yield compares favorably 
with American gas coals and the average, by a small amount, exceeds the 
average yield from English coals. 
The regions represented by this investigation include the largest coal 
fields of the Islands and show wide distribution. Since the character 
of the coal in the Philippines and the facts of the gas tests are so nearly 
the same, conclusions may also be drawn from these results regarding 
the other regions. Furthermore, it is probable that equally good or even 
better results could be obtained from a study of the other coals. 
An investigation of the by-products of the distillation of these coals 
has not been made, but it can be stated that the yield of tar is compara- 
tively small. 
The producer-gas plant depends not only on the production and utiliza- 
tion of the ordinary coal gas but also on the partial combustion of the 
fixed carbon which, in an ordinary gas plant, is left behind. Carbon 
monoxide, the product of the partial combustion, is of comparatively 
low calorific value, much lower than that of the gas produced from the 
volatile combustible matter. This explains the results of the work of 
the United States Geological Survey which show, when viewed from the 
usual steaming standpoint, that the quality of the producer gas “improves 
as one descends in the scale of quality of a coal, the best results being 
obtained from brown lignite.” The same tendency is noted in the gas- 
producing power of native coals, as shown below: 4 
Hew power Acide ma — reer 
of the com- alories per of gas produc er 
Source of the coal. bustible in liter of gas. | kilo of conibustiole 
calories. in calories. 
pe ES Ga Sega ey oa is See 7,305 35 5,710 2% 1,768,000 222 
° 
Et RR ee eee eee 7,015 £2 4,295 °3 1,413,000 =F. 
SIE, SOG Ee Oe ee eee 6,965 Fg | 5,020 SFag | 1,542,000 522% 
TOI a aha sun ck 6 985 ESs 5, 483 E223 1, 626, 000 hes 
ESS ES ed Pa Mc sR 6,735 2 te ie 730¥ 2 r 1,910, 000 $2 
This fact is of importance to the Philippines as it suggests a method 
for the utilization of the low-grade fuels. The disposition of the outcrop 
coal, which must be mined in opening up the works, and the use of the 
slack is the question now to be considered and the problem which we 
must solve. My investigations have been made with outcrop coals of a 
low fuel ratio, with the particular object of determining their utility. 
The above results show that the coals tested have satisfactory gas- 
