314 IMPROVING THE ACCURACY OF TIMBER ESTIMATES 



a history of each individual tree, but the total number of trees in each 

 class is recorded in height classes as follows: 



Overtopped =\' in height; 

 I' = 2' in height; 

 2' = 4' in height; 

 4' = 1" in diameter. 

 Free, same classes. 



By inch classes, 1, 2 and 3 inches. In these inch classes 

 the trees are recorded in five crown classes: x, d, c, i, 

 and s previously indicated. 



References 



" Average Log " Cruise, W. J. Ward, Forestry Quarterly, Vol. V, 1907, p. 268. 

 Errors in Estimating Timber, Louis Margolin, Forestry Quarterly, Vol. XII, 1914, 



p. 167. 

 A Method of Timber Estimating, Clyde Leavitt, Forestry Quarterly, Vol. II, 1904, 



p. 161. 

 Forest Mapping and Timber Estimating as Developed in Maryland, F. W. Besley, 



Proc. Soc. Am. Foresters, Vol. IV, 1909, p. 196. 

 An Efficient System for Computing Timber Estimates, C. E. Dunstan, C. R. Gaffey, 



Forestry Quarterly, Vol. XIV, 1916, p. 1. 

 Timber Estimating in the Southern Appalachians, R. C. Hall, Journal of Forestry, 



Vol. XV, 1917, p. 311. 

 Some Problems in Appalachian Timber Appraisal, W. W. Ashe, Journal of Forestry, 



Vol. XV, 1917, p. 322. 

 Determining the Quality of Standing Timber, Swift Berry, Journal of Forestry, 



Vol. XV, 1917, p. 438. 



Reviews 



Error of Strip Survey .(Sweden), Journal of Forestry, Vol. XVI, 1918, p. 938. 



Estimating for Yield Regulation, Schubert, Forestry Quarterly, Vol. XIII, 1915, 

 p. 399. 



European Methods of Estimating Compared for Accuracy, Forestry Quarterly, 

 Vol. XIV, 1916, p. 521. 



Volume Tables and Felling Results, Forestry Quarterly, Vol. IX, 1911, p. 632. 



Results of Errors in Measuring, Schiffel, Forestry Quarterly, Vol. IX, 1911, p. 628. 



Methods of Estimating Compared, Prof. Zoltan Fekete (Hungary), Forestry Quar- 

 terly, Vol. XIV, 1916, p. 521. 



A New Method of Cubing Standing Timber (Hungary), Forestry Quarterly, Vol. 

 XII, 1914, p. 474. 



