Buatr.—On the Building Materials of Otago. 148 
will not transmit the names of their architects to many succeeding gene- 
rations. 
Although the bad qualities of the Oamaru stone are quite apparent, 
there is, on the other hand, so much to recommend it, that it will always 
be a popular building material. I shall, therefore consider the work for 
which it is well adapted, and the precautions necessary to ensure the best 
results from its use. 
The stone is well suited for any ordinary work in a dry warm climate, 
like Victoria, and it is unexcelled for internal decorations of all kinds and 
in all situations. It is suitable for ecclesiastical architecture generally, 
and forms a beautiful contrast as facings to darker stone. 
It should not be used in the southern side of buildings, particularly if 
they are recessed, and it is altogether unfitted for window-sills, parapets, 
and the upper side of large mouldings and similar projections. Buildings 
of this material should be designed to have as few of these as possible, and 
where unavoidable, the flat tops of the stones might be covered with some 
preservative; from an esthetical point of view, this is the only part of a 
stone building where such should on plea be permitted. Dampness can be 
prevented, to a certain extent, by an impervious foundation and internal 
lining, hollow walls, and other expedients of a similar nature. I have 
made several experiments with Oamaru stone, to test the efficacy of certain 
appliances occasionally used to prevent damp. A bar of dry stone, after 
receiving two coats of ordinary oil paint, was deposited in water. In 40 
hours it had absorbed 84 per cent. of its bulk, including the weight of the 
paint, against 81 per cent. absorbed by unprotected stone in the same time. 
Another sample, coated with soluble glass, the principal indurating 
ingredient in artificial stone, absorbed 27 per cent., exclusive of the weight 
of the solution, which was four per cent. more. 
Although these experiments give an indication of the results to be 
derived from the application of the materials referred to, they are altogether 
too crude to be advanced as conclusive. The oil in the paint was absorbed 
to such an extent by the stone that the colouring matter, which remained 
on the surface, could be washed off by water. It is, therefore, probable 
that much better results would be obtained by more coats, and the use of 
a heavier pigment like red lead. With reference to the use of soluble glass 
as a remedy for damp, I am not sure that this is a property to which it lays 
special claim. Although porosity is a primary cause of decay, it may be 
possible to increase the hardness and durability of stone, without removing 
the lesser evil. Besides, the method of applying the solution adopted by 
me, may not be exactly correct. 
