THE PREFACE 



The development of agricultural lands necessitates a gen- 

 eral knowledge of elementary engineering principles. The 

 purpose of this volume is to explain and illustrate the prac- 

 tical application of these principles. The subjects treated 

 and their method of presentation have been determined by 

 nine years' experience in the class instruction of college, 

 school, and short-course students and by correspondence 

 and personal interviews with men familiar with the needs 

 and desires of the ordinary landowners throughout the coun- 

 try. An effort has been made to eliminate everything of a 

 technical nature and to explain in simple, clear language the 

 engineering problems that most frequently confront the 

 average landowner and agricultural student. The authors 

 believe that the more important subjects are covered in 

 sufficient detail to give the reader the practical information 

 needed on a farm. Undoubtedly work has been omitted 

 which would be of value in certain localities, but it is imprac- 

 ticable, in a book of this nature, to cover all points which 

 might be of interest to special individuals. 



A chapter on surveying has been omitted for well-defined 

 reasons. The expense of instruments and materials for the 

 proper performance of surveying work is such as to eliminate 

 them from farm equipment. The agriculturist is suffi- 

 ciently occupied with the problems presented by roads, 

 drainage, irrigation, buildings, and similar matters, without 

 attempting to master the details of manipulating a survey- 

 ing instrument in the field or making the technical com- 

 putations. For both satisfactory results and economy a 

 trained engineer should be employed to lay out and map 

 proposed improvements. The engineering skill of the agri- 

 culturist can then with profit be limited to the agricultural 

 side of the problem. He should be sufficiently versed in 

 the knowledge of engineering to be able to collect his part of 

 the information and furnish it to the engineer and then 



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