388 . Transactions.—Geology. 
The valuable or heat-giving substances in a coal are the volatile or 
tarry matter and the fixed carbon. Now, on adding together the volatile 
matter and fixed carbon in the above, the Bay of Islands will give 91:14, 
and the Neweastle 93-4 per cent. of heat-giving substances, shewing that 
the latter has slightly the advantage. But the difference is so small that it 
would hardly be noticed in ordinary use. 
The coal to which I have referred as being superior to that imported, is 
found on Mr. Frater’s land at Whareori, near Whangarei, and of which the 
following is the analysis :— 
: (No. 1).—Wauareorr Coat. 
Volatile and organic matter... 0 -e. + 25°50 
aeniie OREN y= agg A a as ts 69°48 
1S ESE Se ag tee eg are OP aa eee 52 
NE se ie ae peg ewe See eee ee 1:70 
Water Ge eS ees eve) ane hs 2°80 
100-00 
On adding together the volatile matter and fixed carbon in this sample, 
the result will be 94-98, or as nearly as possible 95 per cent. of heat-giving 
substances, thereby: shewing an advantage over both the above. But, the 
superiority of this coal does not stop there, for it gives less ash, and what is 
most important to users of steam power, it gives less sulphur. 
I may also mention that this is a coking or caking coal—a very 
important matter, when used for blacksmith work, etc. 
The next coal to which I will refer, is that known as the “ Whangarei 
coal,” and which has, to some extent, been already tried. The following is 
the analysis :— 
(No. 2).—Wauanearer Coan. 
Volatile and organic matter... ... 0... >... 31°40 
eR WE hr Sus ga cee oc = eee 51°60 
i ak a rh as ei a wads san 6-00 
I ae aes, tee ek A ee 2-00 
Water ae ee ae OS aes eee, Pe 9-00 
100-00 
The heat-giving substances in this sample, it will be seen, are consider- 
ably below those of the above coals. But, the distinctive character of this 
coal lies in the proportion of water, which will be seen to exceed that in the 
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