86 
Appendix to the Report of the Jiu/f/cs on 
"Tlie calculated calorific power of such coal, taking the most 
recent determinations of thermal equivalents, viz., 
Carbon 8,080* 
Hj^drogen 34,000 
Sulpluir 2,220 
and assuming all the sulphur to exist as iron pyrites (which is 
not strictly true but near enough for these calculations), shows 
that one part of the coal is capable of raising 8177 parts of water 
from 0^ to 1° centigrade. 
" Com'paring this wdth the calorific power deduced in the 
same way from some of the other coals examined by the Admiralty 
Commission in 18i8, I find that it ranks high, but that there are 
several other coals which are much superior, — 
e.g. Ebbw Vale gives a calorific power of .. 9011 
Powell's Duffryn „ .. 8731 
AVhilc Graigola gives only „ .. 78G7 
The latter is of the same class as Llangennech. 
"The following table shows the analyses of these coals with 
the actual duty obtained in the Admiralty trials, and it will be 
' seen that there is a close correspondence between the relative 
calculated calorific powers and the actual duty obtained, so that 
where the direct experiment cannot be made, the chemical 
analysis affords a pretty safe guide to the value of a coal. On 
comparing my results in 1871 with those obtained by Sir Henry 
de la Beche and Dr. Lyon Playfair in 18i8, it will be found 
that there is a close correspondence, thus showing that a careful 
chemical analysis is able to identify a particular class of coal, 
and also that scams of coal maintain their characteristics over 
considerable areas. 
The trials by the Commission in 1848 and my own analysis 
agree in showing that the coal is surpassed by other steam coals 
of this district, both theoretically and practically. 
"In the Report by the Commission the coal is described thus; 
' These coals have a rather dull appearance, are soft, and have a 
structure almost wholly fibrous. Their fracture is very irregular, 
and the natural softness of the coals renders them easily reduced 
to powder.' 
" This latter fact would account for the large quantity of so- 
called ' soot ' found in the flues, which amounted to 225 lbs. 
from 7682 lbs. coal employed, and, as a necessary consequence, 
for the actual duty being lower than that given by some coals 
of inferior composition. 
* These are French thermometrical degrees of heat into English pounds of 
water, and must be multiplied by rs to compare with the ordinary English ex- 
pressions. 
