I. 3. THE BALSAM FIR. 85 



when it can be had, for the lighter spars of vessels, on account 

 of the smoothness and beauty with which it works. It is found 

 farther north than any other tree of America, and in latitude 

 67£° attains the height of twenty feet or more.* 



This tree has considerable rapidity of growth. Seven trees 

 in the Botanic Garden, Cambridge, which had been planted 

 thirty-one or thirty-two years, measured, one, two feet ten 

 inches ; one, two feet nine inches : three, two feet five inches 

 each ; one, two feet four inches ; and one, two feet three inches ; 

 giving, on an average, a diameter of ten inches in thirty -one 

 years, or a growth of somewhat less than one-third of an inch 

 annually. 



I. 3. The Fir. Picea. Link. 



The firs are lofty trees, social inhabitants of the colder regions 

 of both hemispheres, and often forming vast woods. They are 

 remarkable for the regularity and symmetry of their pyramidal 

 heads. The leaves are solitary, needle-shaped, rigid, semper- 

 virent, supposed by botanists to be formed of two, grown to- 

 gether. They are distinguished from the other pines by the 

 smoothness of their bark, in which are formed cavities or crypts 

 containing their peculiar balsam, by the silvery whiteness of 

 the under surface of the seemingly two-rowed leaves, and by 

 their long erect cones, formed of woody, deciduous scales, with 

 a smooth, thin edge. 



Sp. 1. The Balsam Fir. Picea balsamifera. Michaux. 



Figured in Lambert's Pinus ; Plate 41. 



Michaux ; Sylva, III, Plate 150. 

 Loudon ; Arboretum, VIII, Plate 334. 



This beautiful evergreen resembles the spruce in its regular 

 pyramidal form. It differs from it in its bark, which is smooth 

 when young, and continues so until the tree has attained con- 

 siderable age ; in its leaves, which are nearly flat, and of a beau- 

 tiful silvery color beneath, and in having large, upright cones. 



* Hooker's Fl. Bor. Am. II, 163. 



