30 



James Mann : 



The following Table 2 gives the mean modulus of rupture 

 and the mean modulus of elasticity of the six species, schedules 

 of details being given subsequently : — 



Table 2. 



F. in lbs per sq. in. 



16485 

 8637 

 8185 

 6605 



Name of Timbers. 



Ulabo 

 Tamanau 



Alaga 



Madave 

 Kokoilo 

 Ilimo 



5725 

 4736 



E. in lbs per sq. 



2084250 

 1095200 

 153950U 

 1081350 

 799675 

 795900 



Compression Along the Grain or Column Tests. 



Specimens, cut from the beam tests, were subjected to com- 

 pression along the grain tests, that is, as columns. The dimen- 

 sions were approximately three inches scjuare, the exact figures 

 being given in the schedule of details. The length was twenty 

 inches. The ratio would be nearly l-7th, consequently 

 they would be short columns, and should give the true com- 

 pressive resistance of the materia] in this particular direction. 



Strength in compression is a fair gauge of the relative Cjuality 

 of timber for general work, but does not represent its useful- 

 ness for special purposes, such as cabinet work, etc. 



To ascertain the breaking weight per square inch, the total 

 load producing fracture was divided by the area of the end 

 grain thus W/DB = breaking weight in lbs per square inch, 

 where W = total breaking w^eight or load. 

 B = breadth. 

 D = depth. 



The following Table 3 shows the mean strength in compres- 

 sion of the six species: — 



Table 3. 



Name of Timber. Mean breakiiij;: wciglit in lbs. per sq. inch. 



Ulabo . - . . 9522 



Alaga - - - - 6110 



Madave - - - - 5760 



Tamanau - - - - 5320 



Kokoilo - - - - 4795 



Ilimo ... - 3550 



