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The hardness plays an important part in the use of coals. 
All coals used for a reverberatory furnace should be hard. 
A soft coal will not produce the long flame necessary to fill 
the body of the furnace, and though the heat will be intense 
in the midst of the fuel, it will be local. The best coals for 
these purposes, in the northern part of the coal field, are 
derived from the Better-bed, which is almost entirely free 
from sulphur, and is moderately hard. The Beeston-bed to the 
south-east of Leeds, is about the same hardness as the 
Better-bed, but not so free from sulphur, and the Middle- 
ton-bed coals, from the little seam, have been long used 
for making best iron. But the best of all for hardness 
and long powerftd flame, for keeping clear in the fire bars, 
and for giving a good yield of iron, is the hard coal from 
South Yorkshire, which I consider to be the type of what 
furnace coals, for making iron, should be. The Barnsley 
hards are used in Leeds for making the best Yorkshire 
iron, and the hards of the Parkgate seam are sufficiently 
hard to be used raw for blast furnaces. The Silkstone 
hard coal is used almost exclusively for domestic purposes. 
Although the seams of the northern part of the Coal-field 
are not so hard, and do not yield so much iron as those of 
South Yorkshire, they are much harder than the Durham 
coals used in the Cleveland district. The latter fall away 
into small if exposed. On the whole, we may congratulate 
ourselves on having coals which cannot be surpassed, on 
the possession of large quantities of the best ganister, fire- 
clays, and fire-stones, and also of ironstone, which cannot be 
equalled for strength and durability. 
