! 
REVIEWS. 
The next characteristics taken are weight, texture, hardness, and grain. 
Under weight, Mr. Baker prefers the trade custom of the weight of a cubic 
foot. The-moisture supposed to be in well air-dried timber is 10 to 18 per cent. 
It is the custom in the United States of America to adopt 12 per cent. as a 
standard. It would have improved the references if the specific gravity had 
also been added. No one likes making calculations of division by 62.425. As 
example, at first glance we see H. paniculata (black or white ironbark), respec- 
tively 694 and 64 lbs.; H. globulus (Tasmanian bluegum), 63 lbs., all heavier 
than water. ; 
An excellent section is that dealing with wood structure (pp. 15-21). Here 
is given a good account of what constitutes the timber of commerce, the structure 
of wood fibre, and the relation of per cent. to weight, the relation of hardwood 
and sapwood to colour, &c. This is a section that we would like to see much 
extended, and the other elements of the wood might be illust rated. There are 
seven types of wood fibre shown, and the microscopic examination of the disin- 
tegrated wood elements is often sufficient to identify a timber. This section is 
greatly helped by the many (64) photomicrographs (X45) of cross sections, 
longitudinal, radial, and tangential sections. This requires an enormous amount 
of work, and many blocks, and it is a question whether the method adopted by 
Mr. N. W. Jolly in his illustrations of Queensland timbers (Forestry Bulletin 
"No. 1, Queensland) would not be of more value for the foresters, traders, builders, 
&e. There are photographie pictures of the planed surface—nine on an octavo 
page, of a magnification of two and a half times. They can be further magnified 
hy the reader, by using a hand lens, and so would correspond to the actual 
examination of a hand specimen. ’ 
Amongst the new and interesting features introduced are:— 
1. Hardwoods, in grades of hardness (p. 383), under extremely hard, very 
hard, hard, moderate. 
2. Comparative combustibility of timbers (p. 28). 
3. Lists of timbers suitable for various purposes, eg., for furniture, 
shipbuilding, carriage-making, bridges, sleepers, wharfs, wood pave- 
ments, wood carvings, &e. 
Engineers are not in complete. agreement as to methods of testing hardness of 
timber. The impact method, as approved by Mr. Baker, must be carried out in 
at least three different planes, in relation to the fibres, &e.; and on consulting 
Professor Warren’s and Mr. Julius’ lists and methods, we find a fair amount 
of diversity, e¢.g., Baker—very hard, 2. paniculata; hard, #. acmenoidies, I. 
microcorys, HE. globulus, B. maculata, Syn, laurifolia; while Warren gives almost 
a reversed order—Syn. laurifolia, BH. maculata, LH. paniculata, H. globulus, LH. 
acmenoidies, EH. microcorys. This is a section which requires the co-operation 
of the engineer. 
The section on combustibility brings out the great fire-resistance of H. flet- 
cheri and Syncarpia laurifolia (turpentine), and this property alone justifies 
afforestation of these species. 
Useful hints are to be found under every section, and should result in the 
greater demand for Australian timbers, e.g., under shipbuilding, we see turpen- 
tine for cobra resistance; brown box for wear without splintering; 1. maculata 
for planking below water-line, oWing to flexibility, &e. Mr. Baker strongly 
recommends stringybark for furniture making. 
sii 
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