380 
The N.Z. Journal of Science and Technology. 
[Nov. 
for the remainder colour is of less importance. Coniferous woods are almost exclusively 
used. Hardwoods are not suitable, owing to their hardness, short fibre, and colour, 
as well as their lower yields of pulp per unit of wood. (2.) For the sulphite process the 
same character and quality of wood are required as for the mechanical process, but 
uniformity in the size of the wood is of less consequence. (3.) While the sulphite, process 
is mainly applied to the long-fibred coniferous (soft) woods, the soda process proper 
generally uses the shorter-fibred woods from deciduous trees, the softer or more open¬ 
grained woods, such as the poplars, being preferred, although hardwoods are used where 
local conditions warrant. The natural colour of the wood is of little importance, as 
it is destroyed in the cooking process. Mr. Surface states that only the soda process, 
possibly modified to the sulphate process, is applicable to the Tasmanian hardwoods, 
and he consequently devotes to this process a very ample description. 
In New Zealand the plentiful coniferous timbers are too valuable to use 
for pulp-making, and so, as an abundant supply is most essential, there 
remain, therefore, as possibly suitable only tawhero or kamahi ( Weinmannia 
racemosa), two or possibly three of the beeches (birches) ( Nothofagus spp.), 
tawa ( Beilschmiedia tawa), and possibly taraire (B. tarairi). The small trees 
that in some places occur in great abundance would not yield a sufficient 
volume of wood per acre even if the quality of the wood were suitable. 
The Tasmanian trees on which Mr. Surface experimented were myrtle ( Nothofagus 
Cunninghamii), swamp-gum ( Eucalyptus regnans), blue-gum ( E. globulus), stringy-bark 
(E . obliqua), and silver-wattle ( Acacia dealbata). The woods of these trees were found 
to be very dense and fine-grained, and on this account they would be difficult to pene¬ 
trate with solutions despite their apparent porosity. Like all hardwoods, they were 
found to be rather short-fibred. Stringy-bark had the longest fibres (1-06 mm.) and 
silver-wattle the shortest (0-94mm.); myrtle fibres measured 1-04mm. Aside from 
shortness, all the fibres were found to be uncommonly delicate and slender. From the 
ascertained characteristics of the species he examined, and the preceding specifications 
of the woods required for various processes of pulp-making, the author concludes that 
there is but one process—the soda process—that would be commercially adaptable. 
Mr. Surface sets out in tabulations most comprehensive details of his investigations. 
It was found that the yields of pulp were about 30 per cent., which is much lower than 
the percentage obtained from the woods used in America ; the green woods all con¬ 
tained a very large amount of water ; the bleached pulps produced were approximately 
■equal to any of the commercial soda pulps in suitability for the manufacture of cheap 
writing, envelope, book, magazine, and other related papers. It was found that market¬ 
able soda pulps can be produced from Tasmanian woods, but not sulphite or mechanical 
pulps. 
As regards the utilization of mill-waste, Mr. Surface points out that sawdust, even 
from the long-fibred coniferous timbers, cannot be profitably used for pulp in Europe 
and America; consequently the sawdust from the short-fibred hardwoods would not 
be suitable for pulp. Besides shortness of fibre, sawdust has other serious defects 
that make it unsuitable for pulp. Other forms of mill-waste, when clean and free from 
rot and knots, might be suitable; but when one considers the very large volume of 
timber required by a modern pulping plant it is found that the largest mill in Tasmania 
(after firewood for mill-boilers, &c., is provided) produces only about one-fifth of the 
volume of waste that would be required for a pulp-mill of a minimum capacity of 10 tons 
of pulp a day (the smallest commercially profitable mill). A 10-ton-per-day pulp-mill 
would require a supply of timber not less than 12,500 superficial feet per diem. Duly 
considering these facts, therefore, one must conclude that it would not be at present 
profitable to undertake the pulping of mill-waste in this Dominion. 
Mr. Surface estimates that the capital required for a plant to produce 10 tons of 
pulp every day of twenty-four hours (to operate for twenty years) is £33,700 (in the 
year 1915), exclusive of the outlay required for sawmill, tram-lines, rolling-stock, plant 
to break up the timber, &c., which would be an additional £30,000, or a total of 
£63,700. 
The author concludes that the manufacture in Tasmania of pulp for sale would 
not be a profitable undertaking ; he shows, however, that under very favourable cir¬ 
cumstances the manufacture of pulp and paper into No. 1 book and related printings, 
•cheap writing and envelope papers, would yield a profit over and above interest on 
the investment. It is not, however, reasonable to suppose that circumstances would 
be always most favourable. 
E. P. T. 
