134 



AMERICAN FORESTRY 



wnatcver measure it becomes true, and back of all the 

 wonderful air victories already won, is the industrial 

 story of the building of the machines. Some history 

 should record this too. 



But what of spruce? In truth it is but one of the 

 many materials in the complex mechanism of the mod- 

 ern flying machine. It was not designed nor patented by 

 anyone ; it is not new nor changed ; and is only one of 

 many high-class woods. Yet of all known materials, 

 including both wood and metal, it best meets the require- 

 ments for the supporting framework of aircraft wings. 

 This is confirmed by Mr. 

 F. R. Pendleton, of the Im- 

 perial Munitions Board of 

 Canada, in the statement 

 that "no other wood can 

 take the place of spruce in 

 this work, nor has any sub- 

 stitute been found." The 

 best is certainly none too 

 good, where failure means 

 a fatal fall. 



Again quoting Captain 

 Dourif, "spruce is a vital 

 necessity of airplane con- 

 struction. Our enemies 

 have tried substitutes, but 

 they have been found want- 

 ing." We have the spruce. 

 It is known what it will do 

 in actual service and must 

 be had, although the For- 

 est Service has tested and 

 classified in order of merit 

 the other woods which 

 might be used. The most 

 promising of these are 

 Douglas fir, sugar pine and 

 yellow poplar, and some 

 Douglas fir aircraft stock 

 is being cut. 



Spruce is an aristocrat 

 among woods. Its out- 

 standing characteristics are 

 strength and lightness. 

 With these qualities are 

 combined elasticity and 

 ability to withstand sudden 

 strain and shock. These 

 features of strength hold 

 only within the elastic 

 limit, but its factor of 

 safety is increased by the 

 uniform texture of the 

 slow-growing, carefully selec^d. wood. Of course, if 

 subjected to strains beyond its" strength it breaks like 

 any other wood, but it is dependable in its work up to 

 its maximum load. It gives maximum strength with the 

 lightest weight, when built up or laminated of thin layers 



Photograph by courtesy of James D. Lacey & Company. 



AN INDIVIDUAL PACIFIC COAST SPRUCE OF PROMISING 

 CHARACTER 



Such trees, with long, clean trunks, provide the spruce for wing beams. 

 But not all trees which look promising can be used, because after the 

 labor of felling them and bucking up the lower half into logs, the wood 

 may be found coarse or wavy grained, which is unsuitable. On some 

 areas only 12 per cent of the selected trees meet the specifications. 



like veneer; yet the same qualities predominate in the 

 solid piece. 



It is interesting that the qualities of wood are known, 

 and it is put to its best use, before scientific tests bear 

 out the conclusions and show the reasons for its peculiar 

 fitness for given purposes. The Indians were using 

 spruce canoe paddles when the white man came, and they 

 are the standard today. The same earlier knowledge of 

 adaptability is true of other woods, whether selected for 

 strength, durability, lightness or any combination. There 

 is no record that Solomon maintained research labora- 

 tories, yet he selected cedar 

 for his temple, probably be- 

 cause he knew it was dura- 

 ble. But this would be a 

 story in itself. 



Of spruce, we have all 

 seen it and used it as a 

 matter of course, with lit- 

 tle thought of its special 

 importance until now. We 

 tramp and camp under it 

 in the North woods, most 

 of our newspapers are 

 printed on newsprint con- 

 taining spruce pulp, the 

 sounding boards in our 

 pianos are of spruce, the 

 frame and walls of many 

 buildings are of the same 

 wood. It is a far cry from 

 these everyday uses to a 

 fighting plane downing a 

 Boche 16,000 feet above the 

 shell-torn trenches on the 

 Western front. It would 

 seem quite as incongruous, 

 if we had not been harden- 

 ed by nearly four years of 

 the inconceivable, that our 

 spruce forests are being 

 combed for the wood of 

 which the airplanes of the 

 world are built. But the 

 truth is stranger than fic- 

 tion, and from the farthcr- 

 est separated reaches of 

 our continental forests 

 spruce lumber is being pro- 

 duced, assembled and fab- 

 ricated by special industrial 

 effort and organization, for 

 a purpose more urgent and 

 more vital than the world has ever known. Fortu- 

 nately, America has an adequate supply of spruce 

 for her own needs and for those of her Allies. The 

 enormous difficulties of getting it out in sufficient quan- 

 tity and in time are rapidly being overcome. The normal 



