SOME SCIENTIFIC POINTS IN CABINET MAKING. 
treatment by polishing. The wood is hard, and its peculiarity is that 
the layers of fibre do not possess a good lateral eohesion—are easily 
separated, and must not be sliced, as already stated. Sometimes the 
stony deposit—very likely calcareous, but we never analyzed it—extends 
from the stump many yards into the body of the tree continuously. 
In that case there are usually further deposits through much of the 
trunk between the fibrous laminae. It is then impossible to saw up 
the logs. A frequent trouble with trees of many kinds is that, during 
growth, stones large or small have been. enclosed, or chains and other 
objects, which the saws only discover. But the actual deposition of 
stone by the organs of the tree itself is known to us only in the case 
of the Bombay rosewood. 
The properties of trees and their lumber are most diverse, one of 
the damars, Kauri pine, having the property of shrinking endways when 
cut into boards or baulks. In this it differs from its congeners, and 
indeed from most or all other woods. Why, no one knows, but the 
quality must be taken into serious account or disaster may follow? 
Other woods must be dried with great caution, and with every regard 
for their peculiarities. During the Great War a sudden demand arose 
for certain woods, more especially spruce, and no substitute for it was 
discovered. I have inspected great quantities of spruce in the State 
of Washington and in British Columbia, which were purchased for, 
ostensibly, use in aeroplanes. Much of it was wholly unsuitable, as 
the suppliers themselves considered, and were not slow to declare. But 
the Government buyers were often quite inexpert and incompetent. 
Afterwards I saw in the great aeroplane factories in many parts of 
England the kinds of spruce actually used in the cabinet-making de- 
partments, and would say that the material as finally chosen was 
admirably suited to the work, well handled in the construction, and the 
wood well inspected. Only once was I shown a substitute—cypress— 
and was asked for an opinion by the superintendent. “ Altogether 
unsuitable and dangerous,’ I said. The official said it had been 
authorized, but suddenly an order had come to take out every particle, 
no matter whether in finished or unfinished parts or even completed 
*planes. 
ADHESIVES. 
In the Philadelphia Saturday Hvening Post of 3rd May last is a 
long article, “ What we Learned about Wood,” that is to say during the 
- period of the war. I have not quoted from it, but.it will be found 
interesting. What I do know is that not a single fighting ’plane of 
American construction was used in France up to the end of the war, 
whereas the cabinet shops of England, pianomakers amongst them, — 
quickly adjusted themselves to turning out the most perfect work the 
world has seen. A friend of my own in London, who is a veneer cutter 
on a large scale, indeed the chief dependence of the war authorities 
in that important connexion, invented a special adhesive for securing: 
the laminz of aeroplane propellers. “He happens to be a Fellow of 
the Chemical Society, and was very early on the search. Many 
splendid lives had. been lost’ because of propellers bursting apart, the 
strain being severe during extreme exposure to cold and moisture, with 
rapid changes of temperature. ip 
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