256 Forestry Quarterly. 



Tests of Rocky Mountain Woods for Telephone Poles. By 

 Norman de W. Betts and A. L. Heim. Bulletin 67, U. S. Depart- 

 ment of Agriculture. Washington, D. C. 1914. Pp. 28. 



This paper gives the results of tests on western red cedar, 

 lodgepole pine, and Engelmann spruce poles to determine their 

 suitability for telephone poles'. The tests included fire-killed pine 

 and spruce. Although pine and spruce are not naturally durable 

 in contact with the ground, the general adoption of preservative 

 treatment by railroad and telephone companies would permit their 

 use if otherwise satisfactory. 



On a basis of the fiber stress developed, the air-seasoned lodge- 

 pole pine is superior to the cedar in all of the mechanical pro- 

 perties tested. Fire-killed lodgepole pine proved to be only 80 

 per cent, as strong as the cedar, but in elastic values was prac- 

 tically equal to it. Fire-killed Engelmann spruce was found to 

 be inferior in all mechanical properties to the cedar and pine. 



Since a comparison based on the fiber stress developed is 

 equivalent to one based on uniform ground-line diameter, while 

 in practice it is customary to specify top diameters, it is evident 

 that a difference in taper, such as ordinarily exists between poles 

 of the different woods, would afifect the strength of the poles. On 

 a basis of equal top diameters it appears that there is practically 

 no difference between air-seasoned lodgepole pine and western 

 red cedar, while in stififness the pine exceeds the cedar by about 

 25 per cent. The fire-killed poles of both lodgepole and spruce 

 were practically equal to the cedar in strength at elastic limit and 

 about 20 per cent, below it at maximum load. S. J. R. 



Balsam Fir. By Raphael Zon. Bulletin 55, U. S. Department 

 of Agriculture. Washington, D. C. 1914. Pp. 67. 



This paper deals with all aspects of balsam fir, its distribution, 

 the forest types in which it occurs, the present stand and cut, its 

 economic importance, particularly in relation to the pulp industry, 

 methods and cost of lumbering, life history of the tree, char- 

 acteristics of the wood, rate of growth and yield, and suggested 

 methods of management. 



The total stand of balsam fir throughout its range is roughly 



