iv PREFACE 



an instructor to allow the student to gain a false impression concerning the actual 

 number of data required in an extensive investigation. 



A third object sought is a thorough correlation of the individual fundamental 

 problems in forest mensuration and to show their relation to the larger problems 

 which are usually dependent upon a combination of the fundamentals. It has 

 been sought to accomplish this by keeping the fundamental problems wholly 

 distinct from each other in the early exercises. This should serve to prevent 

 obscuring their broad field of usefulness for other purposes. In the sudceeding 

 exercises the fundamental problems have, however, been combined with the 

 more extensive ones so as to coordinate them and to emphasize their special rela- 

 tionships. The directions for the fundamental problems are also given in consid- 

 erable detail; in the succeeding problems, however, wherein the former are used 

 only as a step in the solution, the student is made to depend upon his knowledge 

 of the methods outlined in preceding problems by having the directions in the 

 latter made more general. 



Nearly all of these problems have been used in about their present form by the 

 students at the University of Washington. Only such changes have been made 

 as were necessary to bring the manuscript up to date and otherwise put it in proper 

 form for publication. 



Although the majority of forest schools now have their work so arranged 

 that in connection with the field work they can obtain data for the greater part of 

 the office problems, every locality does not contain the conditions that would 

 furnish the proper kind of data for all of them. For this reason data have been 

 supplied for use in connection with all of the office problems presented. However, 

 in order to keep the price of the book within reasonable limits it has been neces- 

 sary to limit the quantity of these data included. Though they are therefore not 

 adapted for extensive practice it is hoped they may be of considerable help for 

 illustrative purposes. Wherever these data are supplied in any limited quantity, 

 a special effort was made to select them with reference to average conditions but 

 not so as to destroy their general illustrative value. That the data are only in a 

 few cases presented on the complete field forms should not detract from their 

 value, but should rather help the student to remember just what measurements 

 are required for a certain problem. 



The authors wish to acknowledge their indebtedness to Mr. Bror L. Grondal, 

 of the College of Forestry, University of Washington, and Mr. T. T. Munger 

 and Mr. L. A. Nelson, both of District 6, United States Forest Service, Port- 

 land, Oregon, and to the instructors in other Forest Schools who have used the 

 "Exercises" for helpful suggestions. 



Hugo Winkenwerder. 

 Eli AS T. Clark. 

 University of Washington, 

 January, 1922. 



