22 THE WESTERN HEMLOCK. 



The following table gives the weights of thoroughly kiln-dried Hem- 

 lock and that of four well-known woods, per cubic foot: 



Table 1. — Weight per cubic foot <>f Hemlock and "(her well-known voods. 



Pounds. 



Western Hemlock 26. 95 



Eastern Hemlock 26. 42 



White Pine 24. 02 



Sitka Spruce 26. 72 



Red Fir 32. 14 



The weight given for Western Hemlock is the average of 1,500 feet 

 B. M. taken from different Cascade camps at different times, and was 

 obtained by a member of the Bureau of Forestry. The weights of 

 the other species are quoted from the Tenth Census of the United 

 States, Vol. IX. The weight of Hemlock varies greatly with locality 

 and rate of growth, and in the tree itself. 



DURABILITY. 



The durability of this timber is still largely a matter of conjecture. 

 There are no recorded experiments, and it has until recently been 

 but little used. It is probable, however, that its durability has been 

 greatly underrated. Although not a hardwood, it has given satisfac- 

 toiy service in floors for several years. It is the general experience 

 that Hemlock skids, dams, and bridges in the woods are short lived, 

 but this may be in part because the wood is used unbarked and never 

 becomes dry. Green Hemlock is exceedingly sappy, heavy, and liable 

 to attack by fungi and insects. It is not adapted for use partly in the 

 ground. While the popular prejudice has prevented its extended use 

 for piles, a few instances go to prove that Hemlock piles last almost 

 if not quite as long as those of Fir. In salt water both stand until 

 destroyed by teredoes or limnoria; in fresh water Hemlock lasts about 

 ten years. Hemlock is, however, softer than Fir and more apt to be 

 crushed in driving, and is less able to withstand a great strain success- 

 fully. In ease of working it is between Fir and Spruce, taking a 

 smoother surface and cutting more easilv than the former. It is 

 readily turned, and the straight, even grain renders it free from 

 brashiness or tendency to chip. There is very little contrast between 

 the hard and the soft grain, and this feature, with the absence of 

 pitch, makes it susceptible of a beautiful finish. 



DEFECTS. 



The chief of these are "black streaks" or checks, black knots, and 

 the red heart already described. The latter is serious when the 

 infected wood is used for pulp, on account of the color of the product; 

 as lumber, it is undesirable for ornamental work and prevents substi- 



