f>7s AMERICAN FOREST TREES 



most of it. ID certain restricted localities it is fairly abundant, but there 

 are thousands of square miles in the limits of its range which have not 

 a single tree. Its greatest development is in the south Atlantic states, 

 and in the lower Mississippi basin. 



Trees at their best are from eighty to ninety feet high and from 

 two to four in diameter, but most trunks are less than two feet in diam- 

 eter. The tree frequently forks fifteen or twenty feet from the ground, 

 or occasionally sends up several stems from the ground. Forms of that 

 kind are practically useless for lumber. 



The wood is among the lightest of the birches and weighs 35.91 

 pounds per cubic foot. It is rather hard, medium strong, the heartwood 

 light brown in color, with thick, pale sapwood. It rates below sweet and 

 yellow birch in stiffness, is very porous, but the pores are quite small, 

 and can scarcely be seen without a magnifying glass. They are diffused 

 throughout the entire annual ring. There is no marked difference in 

 the appearance of the springwood and that of the late season. The 

 medullary rays are very small and have little effect on the appearance 

 of the wood, no matter in what way the sawing is done. 



The wood is apt to contain pith flecks and streaks. These are 

 small, brown spots or lines scattered at random through the wood. 

 They are a blemish which is not easily covered up if the wood is to be 

 polished; but they are small and may not be objectionable. The flecks 

 are caused by insects which, early in the season, bore through the bark 

 into the cambium layer (the newly-formed wood), where eggs are 

 deposited. The young insect cuts a tunnel up or down along the cam- 

 bium layer, an inch or less in length and a sixteenth of an inch wide. 

 This gallery subsequently fills with brown deposits which remain perma- 

 nently in the wood. Sometimes these deposits are sufficiently hard to 

 turn the edge of tools. 



River birch is widely used but in small amounts. It may properly 

 be described as a neighborhood wood that is, wherever it grows in 

 considerable quantity it is put to use, but nearly always in a local way. 

 For example, in Louisiana, where it is as abundant as in any other state, 

 it is a favorite material for ox yokes, and no report from that state has 

 been made of its employment for any other purpose. The reason given 

 for its extensive use for ox yokes there is that it is very strong for its 

 weight, and that it resists decay. The yokes there are usually left out of 

 doors when not in use, and the dampness and hot weather cause rapid 

 decay of most woods. The birches are usually listed as quick-decaying 

 woods, but the verdict from Louisiana seems to be that river birch is an 

 exception. 



Plain furniture is made of it, and the manufacturers of woodenware 



