342 



TKSTINC OF TIMMKU. 



In the following table are given the strength properties 

 of some of the timbers, as collected from various sources : 



STRENGTH PROPERTIES OF VARIOUS KINDS 

 OF TIMBER. 



The strength of timber is so very variable, on account 

 of differences in age, climate, soil, time of felling, and 

 seasoning, that the above figures must not be taken as in 

 any way conclusive, but only as rough guides to the 

 results that may be expected from tests. With the 

 exception of the last set, the figures are all taken from 

 Anderson's book, and are, originally, from the experi- 

 ments of Barlow, Bevan, Muschenbrock, and Tredgold. 



Thurston gives the values of the modulus of elasticity 

 for timbers as varying from 447 tons per square inch in 

 the case of white pine to 937 for teak, the mean value 

 for 16 different kinds of timber being 681 tons per square 

 inch, or l,5'25,0001bs. per square inch. 



