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 tamarack ties a year, which reduced to board measure amount to over 150,000,000 feet. Fence posts and telegraph poles come in large numbers from tamarack forests. The wood is stiff and strong, its stiffness being eighty-four per cent of that of long leaf pine, and its strength about eighty per cent. Unusual variations in both strength and stiffness are found. One stick of tamarack may rate twice as high as another. The wood-using factories of Michigan consume nearly 20,000,000 feet of this wood yearly. It is made into boxes, excelsior, pails, tanks, tubs, house finish, refrigerators, windmills, and wooden pipes for waterworks and for draining mines. There is little likelihood that the supply of tamarack will run short in the near future. While it is not in the first rank of the important trees in this country, it is useful, and it is fortunate that it promises to hold its ground against fires which do grave injury to northern forests. In the swamps where the most of it is found the ground litter is too damp to burn. The tree does not grow rapidly, but it usually occupies lands which cannot be profitably devoted to agriculture, and it will, therefore, be let alone until it reaches maturity.