THE PHILIPPINE 
JOURNAL OF SCIENCE 
VOL. 18 MAY, 1921 No. 5 
MECHANICAL TESTS OF SOME COMMERCIAL PHILIP- 
PINE TIMBERS? 
By F. V. VALENCIA 
Mechanical and Testing Engineer, Bureau of Science, Manila 
ONE PLATE AND NINETEEN TEXT FIGURES 
A general knowledge of the mechanical properties of different 
woods is essential to the safe and economical use of timbers for 
any structural purpose. 
This preliminary paper, on the mechanical tests of Philippine 
woods being conducted by the Bureau of Science with the co- 
operation of the Bureau of Forestry, gives data which will serve 
as a basis for the comparison of species as well as for the es- 
tablishment of working stresses. The results given should also 
be of use in determining proper factors of safety in connection 
with the design of timber structures, and in studying the relation 
of the physical characteristics and defects of timber to its 
strength. 
The tests made may be divided into two general series: namely, 
tests of structural timbers, and standard tests of small specimens 
free from defects. 
MATERIAL TESTED 
It is universally agreed that the fundamental qualities of tim- 
ber for structural purposes are strength and durability, but 
the availability of wood in the sizes required and the cost of the 
material often determine what kind of timber should be used in 
* These tests were started by Mr. F. R. Yeasiano with the codperation 
of the writer, and later, when Mr. Ycasiano left the Bureau of Science, 
the writer performed the rest of the tests. 
177655 485 
