10 



According to this table silver maple, honey locust, hardy catalpa, 

 and green ash make their best diameter growth during the first five 

 years. Cotton wood increases its rate of diameter growth from year 

 to year up to the fifteenth, and black walnut up to the twentieth. The 

 rate of diameter growth of the six species for the periods given is in 

 the order named. Hardy catalpa declines rapidly in diameter growth 

 after the twenty-fifth year, cottonwood and green ash after the thir- 

 tieth, and black walnut after the fortieth. Honey locust and silver 

 maple both show a fairly uniform diameter growth to the end of the 

 periods for which figures are given. 



Heartwood composes the central portion of. the stem, and may be 

 distinguished from the sapwood by a difference in color. It is harder 

 and more durable in contact with the ground than sapwood. The pro- 

 portion of heartwood to sapwood increases with the age of the tree. 

 Hence, when durability is required, old trees are more valuable than 

 young ones. 



The contents in fence posts were obtained by ocular estimates in the 

 field. Experience proves this method to be accurate, especially where 

 the trees run small in diameter, as in the great majority of the planta- 

 tions measured. For example, in catalpa plantation No. 4 (p. 15) the 

 survey gave $163 worth of first and second class posts, and the owner 

 cut and sold $167 worth per acre from 4 acres a few months later. 

 In all cases a post was reckoned as 7 feet in length. A second-class 

 post varies from 3 to 3.9 inches and first-class from 4 to 5.9 inches in 

 diameter at the small end. A log 6 to 7.9 inches in diameter at the 

 small end was considered equal to two first-class posts, 8 to 9.9 inches 

 as three first-class, and from 10 to 12 inches as four first-class posts. 

 It will be seen that these dimensions are very liberal. 



To calculate the volume in board feet of cottonwood and black wal- 

 nut, the saw-log length of each tree was determined with a top diameter 

 limit of 6 inches. The standard lengths of logs in Nebraska are 12, 

 14, and 16 feet, with a few 10 and 18 feet, the preferences being in the 

 order named. With these standards as a guide, the trees were divided 

 into saw logs, according to the demands of the trade. From taper 

 measurements curves were drawn, and from these a model tree was 

 constructed by which it was possible to know the diameter of any tree 

 at any height and the diameter of any log at the small end outside the 

 bark. From another set of curves the thickness of the bark of any 

 tree at any height could be determined; therefore the diameter of any 

 log inside the bark. The logs were then scaled by the Doyle rule. 



As a guide in future planting, calculations were made on the cost 

 of and returns from plantations of cottonwood, catalpa, green ash, 

 honey locust, Osage orange, black walnut, and white willow. The 

 figures in each case were based upon a typical example. 



All items of expense were carried with 5 per cent compound inter- 



[Cir. 45] 



