Ill 



Service at such institutions as the Yale Forest School, and the Universities 

 of California, Oregon and Washington. The writer of this paper has been 

 in charge of this Avork since is inception in the year 1903. 



SUBSnifTTfON OF NEW SPECIES. 



The practice of substituting clieaper and weaker species for others 

 which have become scarce and bigli priced lias been increasing for some 

 time. For instance, longleaf pine harvester poles have come into use in 

 place of oak poles, and those parts of vehicles not bearing a great strain 

 are now made of weaker woods. The successful introduction of species 

 which are quite proper for the service is generally retarded by prejudice. 

 Consumers have demanded certain species regardless of their actual fitness, 

 and irrespective of the fact that other and cheaper woods might answer the 

 purpose equally well. For instance, both poplar and red gum, which are 

 now held in such high estimation, have both had to fight their way for a 

 place on the market for such parts ns wagon box boards. 



It may be stated at tlie outset that there is probably none of our east- 

 ern species that can i*eplace hickory for strength and general shock-resist- 

 ing properties and permanence of shape after it is bent. The lines of en- 

 deavor must be to use hickory in only sut^h parts of the wagon where great 

 shock-resisting properties are required, and to correct the rules of grading 

 so that minor defects wbich do not alfect the strength of the wagon are not 

 allowed to operate to throw a suitable piece of hickory out of use. A re- 

 cent study of the properties of the eucalypts in California by the Forest 

 Service seems to point to the value of some of these species for use in 

 wagon construction. The blue gum (Eucalyptus globulus) is the most com- 

 mon species in California, and has competed with black locust for insulator 

 pins, and has given satisfactory service in chisel and hammer handles, and 

 has been used locally for wagon tongues, axles, shafts, spokes, hubs and 

 felloes in California. The wood is hard, strong and tough, and grows very 

 fast. In bending the modulus of rupture is 23,000 pounds per square inch 

 for seasoned lumber, about equivalent to second-growth hickory. This 

 eucalypts seems to be the most promising species upon which to draw for 

 products requiring great .strength, toughness and hardness. 



GRADING RULES. 



An instance of the method of attack to determine the correctness of 

 the grading is in the case of hickory wagon spokes, which are now graded 



