362 



AMERICAN FORESTRY 



single sjwcics of birch. The largest use of its wood is 

 for si)ools the common itinds that are used for thread. 

 Some larger sizes of spools are also made, but most of 

 them are of the 

 .small size. 

 Tooth picks, 

 shoe pegs, and 

 shoe shanks 

 are other im- 

 |)ortant articles 

 made from Pa- 

 per B i r c li 

 wood. 



Of the thirty- 

 five different 

 kinds of Birch 

 trees known in 

 the world, 

 twenty - five 

 reach tree size 

 somewhere 

 within the i r 

 range. Some 

 of them reach 

 tree size in the 

 southern part 



of their range, hut remain quite small toward the north- 

 ern limit of their growth. The birches that venture to- 



THE RANGE OF P.APER BIRCH IN THE UNITED STATES IS INDICATED BY 

 THE AREA NORTH OF THE BLACK LINE. 



wards the Arctic Circle remain quite small, some of them 

 not exceeding twelve to eighteen inches in height. 

 The five species described in this article are the only 



ones of real 

 c o m m e r cial 

 importance in 

 North America. 

 Others, such 

 as the White 

 Birch of Alas- 

 ka and the 

 Western 

 Birch, also 

 reach a size 

 of 75 or more 

 feet in height, 

 but because of 

 their limited 

 range ant' 

 i n a c c essible 

 location are 

 now of little 

 commercial im- 

 portance. The 

 obvious distin- 

 guishing char- 

 acteristics of 

 the five com- 

 mercial birches of eastern North America are given in 

 the following table : 



Photograph by the U. 



Forest Service. 



