EXOGENOUS SERIES -NEEDLELEAF WOODS. 165 



,., i T t. ( Larix americana Michx. 



Tamarack, Larch. j LaHx ^.^ (Du RQ{} 



Nomenclature. (Sudworth.) 



Tamarack, Larch, American Black Larch, Red Larch 

 Larch (local and common (Minn., Mich.). 



names). Juniper (Me., Canada). 



Hackmatack (Me., N. H., 

 Mass., R.I., Del., 111., Mich.) 

 Locality. 



Northern United States and southern Canada, east from Great 

 Lakes. 



Features of Tree. 



Seventy to ninety feet high, one to three feet in diameter. 

 Short pea-green deciduous leaves in tufts. A slender tree, 

 winter aspect gloomy. 



Color, Appearance, or Grain of Wood. 



Heartwood light brown, sapwood nearly white. Coarse conspic- 

 uous grain, compact structure, annual layers pronounced. 



Structural Qualities of Wood. 



Heavy, hard, very strong, durable, resembles spruce. 



Representative Uses of Wood. 



Railway ties, fence-posts, sills, ship timbers, telegraph poles, 

 flagstaffs, etc. 



Weight of Seasoned Wood in Pounds per Cubic Foot. 



38. 

 Modulus of Elasticity. 



1,790,000. 

 Modulus of Rupture. 



12,800. 



Remarks. 



Practically all (tall thin) trunks required for railway ties, posts, 

 masts, etc. Seldom cut into lumber in consequence. Grows 

 in light swamps often extensive and known as tamarack 

 swamp. (Trans. Am. Inst. Mining Engineers, Vol. XXIX, 

 page 157.) 



