RECENT INVESTIGATIONS IN REGARD TO QUALITY OF TIMBER. 279 
XVI. Recent Investigations in Prussia in Regard to the Quality 
of Timber.' By Professor WILLIAM SomERVILLE, M.A., D.Sc., 
D.Cie. 
Since 1890 Professor Schwappach of Eberswalde, and Professors 
Martens and Rudeloff of the Technical Mechanical Experimental 
Institute of Charlottenburg, have been engaged upon a laborious 
investigation into the specific gravity and resistance to crushing 
or pressure of timbers grown in Prussia, which has furnished 
results that cannot fail to be of interest and value to foresters in 
this country. The timbers under experiment comprised Scotch 
Fir, Norway Spruce, Silver Fir, Weymouth Pine, and Beech. It 
was determined to confine attention only to resistance to pressure, 
or crushing lengthwise, as a test of quality; for it has been found 
that, of all tests, this is the one that can be most easily applied, 
and gives most reliable results. 
The extensive character of the work may be gathered from the 
numbers of trees that were submitted to investigation :— 
Scotch fir, : } r ‘ 135 
Norway spruce, : : : 60 
Silver fir, : 5 : 12 
Weymouth pine, ; : : 11 
Beech, . . ; : : 44 
Total, 262 
Each tree examined was selected from amongst, at least, four 
hundred, and was always a stem whose diameter was exactly the 
average of all the others. The tree, having been felled, was 
marked into lengths, the measurement of the lowest length being 
1 metre, while the others were generally four times as long, At 
these various distances complete sections of the stem were taken, 
and it was these sections, or discs, that furnished the material for 
the determinations. (A metre measures nearly 3 feet 3} inches.) 
The accompanying figure shows the method of sampling the 
section. The stem having been cut through at any particular 
distance, the section thus made was marked in the manner 
indicated, the two portions A, B being intended for the pressure 
1 «Untersuchungen iiber Raumgewicht und Druckfestigkeit des Holzes 
wichtiger Waldbaume,” by Dr Adam Schwappach. Berlin, Verlag von 
Springer, 1897 and 1898. 
