AMERICAN FOREST TREES 81 



are very small. The tree is neither a frequent nor abundant seeder. 

 The foliage is thin, and is not sufficient to shut much sunlight from the 

 ground. 



The wood is heavy, hard, very strong, and is durable in contact 

 with the soil. The growth is slow, annual rings narrow, summerwood 

 occupies nearly half the ring, and is dark-colored, resinous, and con- 

 spicuous; resin passages few and obscure; medullary rays numerous 

 and obscure ; color of wood light brown, the sapwood nearly white. 



The uses of tamarack go back to prehistoric times. The Indians 

 of Canada and northeastern United States drew supplies from four 

 forest trees when they made their bark canoes. The bark for the shell 

 came from paper birch, threads for sewing the strips of bark together 

 were tamarack roots, resin for stopping leaks was a product of balsam fir, 

 and the light framework of wood was northern white cedar. 



The roots which best suited the Indian's purpose came from trees 

 which grew in soft, deep mud, where lakes and beaver ponds had silted 

 up. Such roots are long, slender, and very tough and pliant, and may 

 be gathered in large numbers, particularly where running streams have 

 partly undermined standing trees. 



White men likewise made use of tamarack roots in boat building, 

 but the roots were different from what the Indians used. "Instep" 

 crooks were hewed for ship knees. These were large roots, the larger 

 the better. Trees which produced them did not grow in deep mud, for 

 there the roots did not develop crooks. The ship knee operator hunted 

 for tamarack forests growing on a soft surface soil two or three feet 

 deep, underlaid by stiff clay or rock which roots could not penetrate. 

 In situations like that the roots go straight down until they reach the 

 hard stratum, and then turn at right angles and grow in a horizontal 

 direction. The turning point in the root develops the crook of which 

 the ship knee is made. 



Tamarack is seldom of sufficient size for the largest ship knees. 

 Such were formerly supplied by southern live oak; and in that case 

 crooks formed by the union of trunk and large branches were as good 

 as those produced by the union of trunk and large roots. 



Tamarack is still employed in the manufacture of boat knees, but 

 not as much as formerly. Steel frames have largely taken the place of 

 wood in the construction of ship skeletons. Boat builders use tamarack 

 now for floors, keels, stringers, and knees. 



Tamarack has come into much use in recent years. Sawmills cut 

 from it more than 125,000,000 feet of lumber a year. Fourteen states 

 contribute, but most of the lumber is produced in Minnesota, Michigan, 

 and Wisconsin. Railroads in the United States buy 5,000,000 or more 



