Brarr.—On the Building Materials of Otago. 163 
This result is to be expected, for the rocks on that side of the island are too 
old and crystalline to produce a good article. 
The exact locality of the Otepopo slate reef is about half a nite west 
from Charles Peak, at the confluence of a small tributary of the Kauru 
with the main stream. The distance from the township of Herbert in a 
direct line being about eight miles. The land has been taken up by a party 
of Dunedin gentlemen, who have opened out several faces to test the quality 
of the rock ; and about 100,000 slates of all sizes have been split already. 
I visited the locality in February last, and although no work had then been 
done, I could see indications of an abundant supply of the material; and I 
felt satisfied that the discovery was one of the most important ever made in 
Otago. Of course it still remains to be seen whether the quarries will be 
commercially a success. They are in a very inaccessible situation, conse- 
quently a large outlay will be incurred in making a road or tramway to 
bring the slates to a market; and the refuse, which is very great in the 
best quarries, may be so out of proportion to the good slates, that they can- 
not be produced at a reasonable price. I understand that the proprietors 
intend to test the quality of the quarries in a thorough manner first ; and if 
it is proved that the rock exists in sufficiently large blocks and faces to 
admit of being profitably worked, operations will be at once commenced on 
an extensive scale. i 
The locality has been named Ballachulish, after the famous quarries in 
Argyleshire. I trust that, like their great prototype, the Otago quarries 
will become so extensive and important as to prove a mine of wealth to 
their proprietors, and a boon to the country generally. 
Roofing slate is found of all colours, from a creamy white to black, and 
there is also a considerable difference in the texture. 
_ It has been found that the best slates are those of a bluish-grey colour, 
which is the exact tint of the Otago ones. The other essentials are, com- 
pactness of texture, impermeability, and the facility with which they can 
be split parallel and without twist. 
The Otepopo slate possesses all these properties in a pre-eminent degree. 
I placed a Welsh and an Otago slate side by side in water for 48 hours, 
and found that, while the moisture rose from three-eighths to one-half an 
inch in the imported article, it did not rise at all in the colonial, which 
proves that the latter is the more compact and impervious of the two. 
The facility of splitting is also fully established, for the many samples to 
hand are of all thicknesses, and perfectly true to shape; and I have seen 
the slates split well with a common pick, instead of the broad knives used 
y the quarriers. 
Shortly, I believe the Otago slate is little, if anything, inferior to the 
