NEW SOUTH WALES COALS. 183 
the report’ to the Mining Department upon the theoretical 
evaporative power of certain piers I pointed out that “ these re 
ts represent the theoretical, ca c, or evaporative power of the 
samples, z.c., the weight of water Whisk would be conve 
steam by the complete combustion of one pound of each of the 
various coals respective 
“It must, however, be clearly understood that the actual heat- 
producing or evaporative power of a coa oal obtained in practice, 
— very greatly upon the size, construction, and form of both 
and boiler, as well as upon the method of firing or burning, 
d oe many other equally obvious circumstances ; it will, 
alike, as was oy tke case in the passes trials.” 
Analysis of the Ash.—The ash was prepared for analysis by 
incinerating the powdered coal in a muffle furnace at a dull red 
heat ; in order to obtain the ash as expeditiously as possible from 
a fairly large quantity of coal, a tray 10 x 6 x 1 inch feos. ae made 
out of stout platinum foil, was used for the incineration 
Silica, alumina, iron, lime, &c. ; the alkalies were de 
Separate portions Dr. J. Lawrence Smi rocess, i.¢, by 
fusion with calcium carbon ammonium chlori 
d : 
The phosphoric and sulphuric acids were also determined in 
separate portions of the ash ; as the proportion of phosphoric acid, 
where present, was shown by rth qualitative tests to be small, 
the molybdic acid process was employed, about two grammes weight 
of ash being taken in duplicate in each case 
NORTHERN DISTRICT. 
Waratah COoLuigRY. 
A. coop firm, bright coal, with well-mark ked lines of lamination, 
bright layers preponderate. Fracture fairly even, breaking into 
cuboidal masses. Layers of fibrous ‘¢mineral ¢ arcoal ” or “mother- 
of-coal” in between the bright layers; these are also to be observed 
in nearly all the other coals. 
Specilie gravity, 1-303. 
Proximate Petes 
Moi 2" oe 
Volatile hydrocarbons Sie oe 
Fixed carbon hc 532 Coke, 59°97 percent. 
Sulphur rete 12 
; 100-00 
ROP omg ee ee 
* Report of the Mining Department, Sydney, 1877, p. 207. 
